阅读说明：本技术 一种含甲基丙烯酸结构的双马来酰亚胺树脂及其制备方法 (Bismaleimide resin containing methacrylic acid structure and preparation method thereof ) 是由 华文强 陈少云 卓东贤 瞿波 郑燕玉 刘小英 于 2020-12-24 设计创作，主要内容包括：本发明提供了一种含甲基丙烯酸结构的双马来酰亚胺树脂及其制备方法。按摩尔计,将100份双马来酰亚胺与200份芳香族二胺进行预反应,再加入0.01～1份催化剂、0～0.5份阻聚剂和100～400份甲基丙烯酸缩水甘油醚发生接枝反应,得到含光敏性甲基丙烯酸基团的双马来酰亚胺树脂。本发明提供的双马来酰亚胺树脂既保留了传统双马来酰亚胺树脂优异的耐热与高机械性能的特性,又可以通过紫外光照射来实现其固化,尺寸收缩率低,有效解决了其成型性差的缺点,而且具有固化速度快、生产效率高、污染小、节省能源等优点。(The invention provides a bismaleimide resin containing a methacrylic acid structure and a preparation method thereof. According to the molar ratio, 100 parts of bismaleimide and 200 parts of aromatic diamine are subjected to pre-reaction, and then 0.01-1 part of catalyst, 0-0.5 part of polymerization inhibitor and 100-400 parts of glycidyl methacrylate are added to perform a grafting reaction, so that the bismaleimide resin containing photosensitive methacrylic groups is obtained. The bismaleimide resin provided by the invention not only keeps the excellent heat resistance and high mechanical property of the traditional bismaleimide resin, but also can be cured by ultraviolet irradiation, has low dimensional shrinkage, effectively solves the defect of poor formability, and has the advantages of high curing speed, high production efficiency, low pollution, energy conservation and the like.)

1. A preparation method of bismaleimide resin containing a methacrylic acid structure is characterized in that: the preparation process is carried out in air or inert atmosphere, and comprises the following steps:

(1) mixing 100 parts of bismaleimide and 200 parts of aromatic diamine in terms of mole, adding 80-300 parts of organic solvent and 0.01-2 parts of catalyst, and reacting at 40-80 ℃ for 0.1-24 hours to obtain a solution A;

(2) removing the organic solvent by a method of decompression concentration to obtain a viscous liquid B;

(3) adding 0.01-1 part of catalyst and 0-0.5 part of polymerization inhibitor into the viscous liquid B by weight, slowly dropwise adding 100-400 parts of glycidyl methacrylate, and reacting at 40-90 ℃ for 0.5-36 hours to obtain the maleimide resin containing methacrylic acid, wherein the structural formula of the maleimide resin is as follows:

P：or H

2. The method for preparing a bismaleimide resin containing a methacrylic structure as claimed in claim 1, wherein: the bismaleimide is N, N '-1, 3-phenylene bismaleimide, 4' -diphenylmethane bismaleimide or a combination of the two.

3. The method for preparing a bismaleimide resin containing a methacrylic structure as claimed in claim 1, wherein: the aromatic diamine is 4,4 '-diaminodiphenylmethane, p-phenylenediamine, 2' -dimethyl-4, 4 '-diaminobiphenyl, 4' -diaminodiphenyl ether or their combination.

4. The method for preparing a bismaleimide resin containing a methacrylic structure as claimed in claim 1, wherein: the organic solvent is acetone, dichloroethane, tetrahydrofuran, chloroform, ethyl acetate, acetonitrile or a combination thereof.

5. The method for preparing a bismaleimide resin containing a methacrylic structure as claimed in claim 1, wherein: the catalyst in the step (1) is glacial acetic acid, zinc chloride or the combination of the glacial acetic acid and the zinc chloride.

6. The method for preparing a bismaleimide resin containing a methacrylic structure as claimed in claim 1, wherein: the catalyst in the step (3) is tetrabutylammonium bromide, tetrabutylammonium chloride, tetraethylammonium bromide, tetrabutylammonium hydrogen sulfate, benzyltriethylammonium chloride, trioctylmethylammonium chloride, dodecyltrimethylammonium chloride, tetradecyltrimethylammonium chloride or a combination thereof; the polymerization inhibitor is hydroquinone, methyl hydroquinone, p-hydroxyanisole, 2-tertiary butyl hydroquinone, 2, 5-ditertiary butyl hydroquinone or the combination thereof.

7. The method for preparing a bismaleimide resin containing a methacrylic structure as claimed in claim 1, wherein: the polymerization inhibitor in the step (3) is hydroquinone, methyl hydroquinone, p-hydroxyanisole, 2-tertiary butyl hydroquinone, 2, 5-di-tertiary butyl hydroquinone or a combination thereof.

Technical Field

The invention relates to the technical field of ultraviolet curing materials, in particular to bismaleimide resin containing a methacrylic acid structure and a preparation method thereof.

Background

Ultraviolet (UV) curing is a type of radiation curing, which is a process that uses ultraviolet light to initiate the rapid conversion of a chemically reactive liquid material into a solid material. The ultraviolet curing technology is considered as an environment-friendly green technology, also called as 3E technology, namely energy-saving, environment-friendly and economical. The ultraviolet light curing resin is a photosensitive resin with relatively low molecular weight, and has groups capable of performing light curing reaction, such as various unsaturated double bonds or epoxy groups. At present, ultraviolet curing resin mainly comprises epoxy acrylate, polyurethane acrylic resin and polyester acrylic resin. Although these resins can be used in many fields at present, they generally have poor water resistance and high temperature resistance and large curing shrinkage. Therefore, the development of a novel high-performance ultraviolet curing resin is of great practical significance.

Bismaleimide (BMI) is a high-performance thermosetting resin and has the advantages of good dielectric property, high glass transition temperature, excellent thermal stability and the like. The high-temperature-resistant composite material is usually used as an advanced composite material matrix, a high-temperature-resistant insulating material, a high-temperature-resistant structural adhesive and the like, and is widely applied to the fields of aerospace, transportation, mechanical electronics and the like. At present, the BMI curing mode is thermal curing, and the most defects are that the curing temperature is high, the production period is long, the residual stress of the cured resin is large, the excellent performance of the resin is difficult to fully exert, and the like. Therefore, how to obtain better curing process conditions becomes one of the important contents of the research on the BMI modification. Compared with other curing methods, the Ultraviolet (UV) curing technology has the advantages of high curing speed, high production efficiency, low pollution, energy conservation, cost reduction and the like. Therefore, the research of the high-performance BMI resin capable of being cured by ultraviolet light actively has important theoretical significance and application value.

At present, many reports are made about photosensitive BMI resin at home and abroad, and two main synthetic methods are provided:

the first synthesis method is to graft a photosensitive group on bismaleimide. In "a polyimide photosensitive material for 3D printing" (wang dao long chinese patent, 105837760,2016-08-10), it is reported that 4,4 ' -bismaleimide diphenylmethane reacts with 3,3 ' -dihydroxy-4, 4 ' -diaminodicyclohexylmethane, maleic anhydride, and then reacts with glycidyl acrylate to attach a photosensitive group. However, this technique has the disadvantages: 1) the synthesis steps are relatively complicated and difficult to industrialize; 2) too many non-five-membered ring and six-membered ring structures are introduced, so that the heat resistance and mechanical property loss of the BMI is serious; 3) only 2 photosensitive groups are needed, so that the UV curing activity is difficult to control, and the photocuring speed is slow.

The second synthesis method is that bismaleimide and some substances are subjected to simple reaction or physical blending to obtain a resin solution. In the document "UV curing of a liquid based biochemical-associating Polymer system" (Fan, Boey, et al. express Polymer Letters,2007,1(6): 397-. However, this technique has the disadvantages: 1) the reaction activity of BMI is not high, so that the addition of BMI reduces the photocuring capacity of the resin composition; 2) during the curing process, N-acryloyl morpholine oligomer is generated, thereby reducing the thermal stability of the copolymer and leading to lower degradation temperature.

Aiming at the defects of the existing BMI photosensitive resin preparation method, the research and development of a novel bismaleimide resin with excellent performance and simple synthesis process has important application value and academic significance.

Disclosure of Invention

In view of the situations and deficiencies of the prior art, the present invention aims to provide a bismaleimide resin containing a methacrylic structure and a preparation method thereof. The methacrylic acid-containing bismaleimide resin provided by the invention has excellent heat resistance and low dimensional shrinkage.

In order to achieve the technical purpose, the invention adopts the technical scheme that:

a preparation method of bismaleimide resin containing a methacrylic acid structure comprises the following steps:

(1) mixing 100 parts of bismaleimide and 200 parts of aromatic diamine in terms of mole, adding 80-300 parts of organic solvent and 0.01-2 parts of catalyst, and reacting at 40-80 ℃ for 0.1-24 hours to obtain a solution A;

(2) removing the organic solvent by a method of decompression concentration to obtain a viscous liquid B;

(3) adding 0.01-1 part of catalyst and 0-0.5 part of polymerization inhibitor into the viscous liquid B by weight, then slowly dropwise adding 100-400 parts of glycidyl methacrylate, and reacting at 40-90 ℃ for 0.5-36 hours to obtain the maleimide resin containing methacrylic acid, wherein the structural formula is as follows:

P：

preferably, the bismaleimide is one or two of N, N '-1, 3-phenylene bismaleimide or 4, 4' -diphenylmethane bismaleimide.

Preferably, the aromatic diamine is 4,4 '-diaminodiphenylmethane, p-phenylenediamine, 2' -dimethyl-4, 4 '-diaminobiphenyl, 4' -diaminodiphenyl ether, or a combination thereof.

Preferably, the organic solvent is acetone, dichloroethane, tetrahydrofuran, chloroform, ethyl acetate, acetonitrile or a combination thereof.

Preferably, the catalyst in step (1) is glacial acetic acid, zinc chloride or a combination of the two.

Preferably, the catalyst in step (3) is tetrabutylammonium bromide, tetrabutylammonium chloride, tetraethylammonium bromide, tetrabutylammonium hydrogen sulfate, benzyltriethylammonium chloride, trioctylmethylammonium chloride, dodecyltrimethylammonium chloride, tetradecyltrimethylammonium chloride, or a combination thereof.

Preferably, the polymerization inhibitor in step (3) is hydroquinone, methyl hydroquinone, p-hydroxyanisole, 2-tert-butyl hydroquinone, 2, 5-di-tert-butyl hydroquinone or a combination thereof.

Compared with the prior art, the invention has the beneficial effects that:

(1) the bismaleimide resin provided by the invention has the advantages of wide raw material source, low price and simple synthesis process, and is suitable for large-scale production and application.

(2) The bismaleimide reacts with the aromatic diamine, the excellent characteristics of the traditional bismaleimide resin are kept from the structure, and the bismaleimide has good mechanical properties and heat resistance.

(3) By grafting photosensitive groups, the BMI polymer realizes ultraviolet curing, and the defect of poor formability is effectively overcome. The BMI polymer has the advantages of high production efficiency, low size shrinkage, little pollution and energy conservation through ultraviolet curing.

(4) Through structure regulation and control, 1-4 methacrylic acid groups with photosensitivity can be grafted, so that the UV photocuring activity is controllable, and BMI polymers with different UV activities can be obtained according to the requirements of a curing system.

Drawings

FIG. 1 is a reaction involved in the process for preparing a methacrylic-containing bismaleimide resin of the present invention.

FIG. 2 is an infrared spectrum of the maleimide resin prepared in example 1 of the present invention.

FIG. 3 shows the nuclear magnetic hydrogen spectrum of bismaleimide resin prepared in example 1 of the present invention (¹H-NMR)。

FIG. 4 is a thermogravimetric analysis (TGA) curve of bismaleimide resins prepared in example 1 of the present invention under nitrogen atmosphere with a temperature rise rate of 10 deg.C/min.

Detailed Description

Example 1

Acetone is taken as a solvent, 35.8g of diphenylmethane Bismaleimide (BDM) and 39.6g of diaminodiphenylmethane (DDM) are added, then 0.04g of glacial acetic acid is added, and the mixture reacts for 2 hours at the temperature of 60 ℃ to prepare an intermediate (BDM-DDM); then removing the acetone by a method of decompression concentration.

0.1g of tetraethylammonium bromide and 0.04g of hydroquinone were added, and then 28.4g of Glycidyl Methacrylate (GMA) was slowly added dropwise and reacted at 60 ℃ for 6 hours to obtain a bismaleimide resin containing a methacrylic acid structure (BDM-DDM-GMA 1).

Referring to FIG. 2, there is shown an infrared (FTIR) spectrum of a maleimide-based resin prepared in accordance with example 1 of the present invention. From the BDM-DDM graph it can be seen that: 3450 to 3360cm^-1Is primary amine-NH₂The stretching vibration absorption peak of (1); 3000-2800 cm^-1Peak at is post-imide cycloaddition-CH₂-a stretching vibration absorption peak; at 1615cm^-1The peak is the bending vibration peak of-NH; 690cm in BDM curve^-1The peak at (a) disappears in the BDM-DDM diagram, indicating that the C ═ C double bond on the imide ring undergoes Michael addition reaction with the amino group. At the same time, 1712cm^-1The nearby peaks did not disappear, indicating that the reaction did not affect the imide group, and that BDM-DDM reacted successfully. Comparison of the Infrared Spectrum of BDM-DDM-GMA and BDM-DDM at 943cm^-1A distinct absorption peak appears in the vicinity, which is the methylene group formed after the epoxy group has reacted with the amino group in GMA. The appearance of the peak indicates successful grafting of the GMA. In addition, the ester bond is 1294cm^-1And 1169cm^-1The symmetric stretching vibration peak is enhanced, which also indicates the success of the GMA and BDM-DDM reaction.

Referring to FIG. 3, which is a nuclear magnetic hydrogen spectrum of the maleimide-based resin prepared in example 1 of the present invention, (b)¹H-NMR)。

Referring to FIG. 4, it is a thermogravimetric analysis (TGA) curve of bismaleimide resins prepared in example 1 of the present invention under nitrogen atmosphere with a temperature rise rate of 10 deg.C/min. The initial thermal decomposition temperature is 307 ℃, the maximum decomposition temperature is 412 ℃, and the carbon residue rate at 800 ℃ is 39.5%; showing that the bismaleimide resin containing methacrylic acid has good heat resistance.

The obtained bismaleimide resin containing methacrylic acid was uniformly coated on a glass plate, and then irradiated with 365nm ultraviolet light (100 mW/cm)²) And (5) irradiating in an ultraviolet curing box under irradiation. And pouring the prepared resin into a grinding tool, and after the resin is completely cured by ultraviolet light, the surface of the product is smooth, and the Shore hardness is 80 HD.

Example 2

Using trichloromethane as a solvent, adding 35.8g of diphenylmethane Bismaleimide (BDM) and 39.6g of diaminodiphenylmethane (DDM), then adding 0.08g of glacial acetic acid drop, and reacting for 2 hours at 60 ℃ to obtain an intermediate; and then removing the trichloromethane by a method of decompression concentration.

Then 0.2g tetraethylammonium bromide and 0.05g hydroquinone are added, and then 56.8g Glycidyl Methacrylate (GMA) is slowly dropped and reacted for 8 hours at 60 ℃, thus obtaining the bismaleimide resin BDM-DDM-GMA 2.

The obtained bismaleimide resin containing methacrylic acid was uniformly coated on a glass plate, and then irradiated with 365nm ultraviolet light (100 mW/cm)²) And (5) irradiating in an ultraviolet curing box under irradiation. And pouring the prepared resin into a grinding tool, and after the ultraviolet curing is completed, the surface of the product is smooth, and the Shore hardness is 65 HD.

Example 3

Using dichloroethane as a solvent, adding 35.8g of diphenylmethane Bismaleimide (BDM) and 21.6g of p-Phenylenediamine (PD), then adding 0.04g of zinc chloride, and reacting at 60 ℃ for 2 hours to obtain an intermediate (BDM-PD); then removing dichloroethane by a method of concentration under reduced pressure.

Then, 0.5g of tetrabutylammonium chloride and 0.2g of methylhydroquinone were added thereto, and then 28.4g of Glycidyl Methacrylate (GMA) was slowly added dropwise thereto, followed by reaction at 90 ℃ for 3 hours to obtain a bismaleimide resin (BDM-PD-GMA) containing a methacrylic acid structure.

The obtained bismaleimide resin containing methacrylic acid was uniformly coated on a glass plate, and then irradiated with 365nm ultraviolet light (100 mW/cm)²) And (5) irradiating in an ultraviolet curing box under irradiation. And pouring the prepared resin into a grinding tool, and after the resin is completely cured by ultraviolet light, the surface of the product is smooth, and the Shore hardness is 55 HD.

Example 4

Acetone is taken as a solvent, 26.8g of N, N' -1, 3-phenylene bismaleimide (PDM) and 39.6g of diaminodiphenylmethane (DDM) are added, then 2.0g of glacial acetic acid is added, and the mixture is reacted for 2 hours at the temperature of 60 ℃ to prepare an intermediate (PDM-DDM); then removing the acetone by a method of decompression concentration.

0.8g of tetraethylammonium bromide and 0.4g of hydroquinone are added, then 28.4g of Glycidyl Methacrylate (GMA) is slowly dropped and reacted at 60 ℃ for 12 hours to prepare the bismaleimide resin containing a methacrylic acid structure (PDM-DDM-GMA).

The obtained bismaleimide resin containing methacrylic acid was uniformly coated on a glass plate, and then irradiated with 365nm ultraviolet light (100 mW/cm)²) And (5) irradiating in an ultraviolet curing box under irradiation. And pouring the prepared resin into a grinding tool, and after the ultraviolet curing is completed, the surface of the product is smooth, and the Shore hardness is 75 HD.

Example 5

Tetrahydrofuran is used as a solvent, 26.8g N, N '-1, 3-phenylene bismaleimide (PDM) and 36.8g of 4, 4' -diaminodiphenyl ether (DB) are added, then 0.1g of glacial acetic acid is added, and the mixture reacts for 18 hours at 50 ℃ to prepare an intermediate (PDM-DB); then removing tetrahydrofuran by a method of decompression concentration.

Then 0.1g of trioctylmethylammonium chloride and 0.08g of 2, 5-di-tert-butylhydroquinone were added, and 56.8g of Glycidyl Methacrylate (GMA) was slowly added dropwise and reacted at 60 ℃ for 6 hours to obtain a bismaleimide resin (PDM-DBD-GMA) containing a methacrylic acid structure.

The obtained bismaleimide resin containing methacrylic acid was uniformly coated on a glass plate, and then irradiated with 365nm ultraviolet light (100 mW/cm)²) And (5) irradiating in an ultraviolet curing box under irradiation. And pouring the prepared resin into a grinding tool, and after the ultraviolet curing is completed, the surface of the product is smooth, and the Shore hardness is 70 HD.

Example 6

Taking tetrahydrofuran and ethyl acetate as a solvent, adding 26.8g N, N '-1, 3-phenylene bismaleimide (PDM) and 36.8g of 4, 4' -diaminodiphenyl ether (BD), then adding 0.08g of glacial acetic acid and 0.02g of zinc chloride, and reacting at 50 ℃ for 24 hours to obtain an intermediate (PDM-BD); then removing tetrahydrofuran and ethyl acetate by a method of decompression concentration.

Then adding 1.0g of tetraethylammonium bromide, a dodecyl trimethyl ammonium chloride composition, 0.5g of hydroquinone and a p-hydroxyanisole composition, slowly dropwise adding 28.4g of Glycidyl Methacrylate (GMA), and reacting at 70 ℃ for 6 hours to obtain the bismaleimide resin (PDM-BD-GMA) containing a methacrylic acid structure.

The obtained bismaleimide resin containing methacrylic acid was uniformly coated on a glass plate, and then irradiated with 365nm ultraviolet light (100 mW/cm)²) And (5) irradiating in an ultraviolet curing box under irradiation. And pouring the prepared resin into a grinding tool, and after the ultraviolet curing is completed, the surface of the product is smooth, and the Shore hardness is 68 HD.

Example 7

Acetonitrile is used as a solvent, 35.8g of diphenylmethane Bismaleimide (BDM) and 39.6g of diaminodiphenylmethane (DDM) are added, then 0.04g of glacial acetic acid is added, and the reaction is carried out for 8 hours at 60 ℃ to prepare an intermediate (BDM-DDM); then removing the acetonitrile by a method of decompression concentration.

Then, 0.8g of tetradecyltrimethylammonium chloride and 0.2g of hydroquinone were added thereto, and then 28.4g of Glycidyl Methacrylate (GMA) was slowly added dropwise thereto, followed by reaction at 40 ℃ for 24 hours to obtain a bismaleimide resin containing a methacrylic acid structure (BDM-DDM-GMA 3).

The obtained bismaleimide resin containing methacrylic acid was uniformly coated on a glass plate, and then irradiated with 365nm ultraviolet light (100 mW/cm)²) And (5) irradiating in an ultraviolet curing box under irradiation. And pouring the prepared resin into a grinding tool, and after the ultraviolet curing is completed, the surface of the product is smooth, and the Shore hardness is 50 HD.

Example 8

Acetone is taken as a solvent, 26.8g N, N' -1, 3-phenylene bismaleimide (PDM) and 39.6g diaminodiphenylmethane (DDM) are added, then 0.06g glacial acetic acid is added, and the reaction is carried out for 16 hours at the temperature of 80 ℃ to prepare an intermediate (BDM-DDM); then removing the acetone by a method of decompression concentration.

Then, 0.5g of tetrabutylammonium hydrogen sulfate and 0.1g of methylhydroquinone were added thereto, and 28.4g of Glycidyl Methacrylate (GMA) was slowly added dropwise thereto to carry out a reaction at 90 ℃ for 36 hours, thereby obtaining a bismaleimide resin (PDM-DDM-GMA) having a methacrylic structure.

The obtained bismaleimide resin containing methacrylic acid was uniformly coated on a glass plate, and then irradiated with 365nm ultraviolet light (100 mW/cm)²) And (5) irradiating in an ultraviolet curing box under irradiation. And pouring the prepared resin into a grinding tool, and after the ultraviolet curing is completed, the surface of the product is smooth, and the Shore hardness is 45 HD.