Flame-retardant maleimide copolymer and preparation method thereof

Abstract

The invention relates to a flame-retardant maleimide copolymer and a preparation method thereof, and belongs to the technical field of high polymer material synthesis. The structural formula of the flame-retardant maleimide copolymer is as shown in formula (I), wherein R can be independently selected from one or more of benzene ring, diphenylmethane and cyclohexane; the value ranges of X, Y, Z and N are respectively 50-200. The material disclosed by the invention has the advantages of efficient flame retardance, low phosphorus and nitrogen content, low combustion toxicity and better heat resistance and mechanical property. The preparation method is easy to control and industrialize. # imgabs0 #

Description

Technical Field

[0001] The invention relates to a flame-retardant maleimide copolymer and a preparation method thereof, belonging to the technical field of polymer material synthesis. Background Art

[0002] Acrylonitrile-butadiene-styrene terpolymer (ABS) resin has excellent mechanical properties with balanced rigidity, hardness and toughness, and its coloring performance, surface gloss, processing fluidity, dimensional stability, low temperature resistance and chemical resistance are also very excellent. In recent years, it has been widely used in automotive equipment, electronic communications, household appliances, mechanical industry, etc., so its heat resistance and flame retardant properties have attracted much attention. However, ABS resin has a low heat deformation temperature and LOI of only 18%, and is easy to burn. When used in various high-temperature resistant electronic and electrical products, it needs to be modified to meet the requirements of heat resistance and safety and fire protection. In order to improve the heat resistance of ABS resin and the like, maleimide copolymers are mainly used as heat resistance imparting materials, such as CN102282183A, CN 103570857A, and CN116751327A; in addition, in order to improve the flame retardant properties of ABS resin, halogen flame retardants, inorganic filler flame retardants, nitrogen-phosphorus flame retardants, etc. are currently most widely used. The Chinese invention patent application with application number 202310772534.5 discloses a halogen-free flame retardant modified ABS plastic and its synthesis process, which uses nitrogen-phosphorus styrene-acrylonitrile copolymer as a halogen-free flame retardant, maleic anhydride grafted ABS as a compatibilizer, and calcium carbonate as a reinforcing agent to compound with ABS resin to obtain halogen-free flame retardant modified ABS, but it is unable to solve the problems of flame retardancy, heat resistance and mechanical properties of the material at the same time. Tang Anbin, Huang Jie, Wang Qian, et al. Synthesis and industrial test study of flame retardant 2,4,6-tris(2,4,6-tribromophenoxy)-1,3,5-triazine [J], Fine Chemicals, 2007, 24(10):1011-1014. This article discloses an example of flame retardant ABS formulation using brominated triazine and the preparation of flame retardant ABS material. This method can obtain V-0 grade flame retardant ABS, but its heat resistance and mechanical properties need to be improved. Summary of the invention

[0003] The first object of the present invention is to provide a novel flame retardant maleimide copolymer.

[0004] In order to achieve the first object of the present invention, the flame retardant maleimide copolymer has the structural formula shown in formula (I):

[0005]

[0006] Wherein, the R can be independently selected from one or more of benzene ring, diphenylmethane, and cyclohexane;

[0007] The value ranges of X, Y, Z, and N are 50 to 200 respectively.

[0008] In a specific embodiment, the flame retardant maleimide copolymer has a number average molecular weight of 30,000 to 100,000, a polydispersity coefficient of 1.8 to 2.3, and a glass transition temperature of 190 to 220°C.

[0009] The second object of the present invention is to provide a method for preparing the flame retardant maleimide copolymer.

[0010] To achieve the second object of the present invention, the method comprises:

[0011] A. reacting triallyl isocyanurate and 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide to obtain a reactive flame retardant monomer TAIC-DOPO;

[0012] B. The reactive flame retardant monomer TAIC-DOPO is polymerized with styrene, maleic anhydride and maleimide monomers to obtain a flame retardant maleimide copolymer.

[0013] The structural formula of the reactive flame retardant monomer TAIC-DOPO is as follows (II):

[0014]

[0015] In a specific embodiment, the molar ratio of the maleimide monomer, styrene, maleic anhydride and reactive flame retardant monomer TAIC-DOPO is 10-15:30-35:2-3:0.1-2.

[0016] In a specific embodiment, the reaction in step A comprises mixing a solvent, 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide DOPO and triallyl triazine trione under a protective atmosphere, and reacting at 140-160° C. for 1-3 hours;

[0017] The molar ratio of the 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide to triallyl triazine trione is preferably 2:1.

[0018] In a specific embodiment, the solvent for the polymerization reaction in step A is at least one of tetrahydrofuran, butanone, cyclohexanone, methyl ethyl ketone, methyl isobutyl ketone, 1,4-dioxane, and sulfolane.

[0019] In a specific embodiment, the solvent for the polymerization reaction in step A and step B is at least one of tetrahydrofuran, butanone, cyclohexanone, methyl ethyl ketone, methyl isobutyl ketone, 1,4-dioxane, and sulfolane.

[0020] In a specific embodiment, the initiator of the polymerization reaction in step B is at least one of azobisisobutyronitrile, azobisisoheptylnitrile, di-tert-butyl peroxide, diisopropylbenzene peroxide, benzoyl peroxide, cyclohexanone peroxide, tert-butyl perbenzoate, and 1,1-di(tert-butylperoxy)-3,3,5-trimethylcyclohexane.

[0021] In a specific embodiment, the polymerization reaction in step B is heated to 80-100° C. under a protective atmosphere and reacted for 4-8 hours.

[0022] The protective atmosphere described in the present invention is a gas that does not react with the reaction system, such as nitrogen.

[0023] In a specific embodiment, the method further includes step C: after the polymerization reaction is completed, a vacuum roller scraper is used to remove the solvent, wash, and vacuum dry to obtain a flame-retardant maleimide copolymer resin, and the washing solution is preferably at least one of ethanol, methanol, acetone, and chloroform.

[0024] The third object of the present invention is to provide a novel flame retardant maleimide copolymer modified ABS resin.

[0025] To achieve the third object of the present invention, the ABS resin contains the flame retardant maleimide copolymer or the flame retardant maleimide copolymer prepared by the above method; preferably, the flame retardant maleimide copolymer is added in an amount of 1% to 40% by weight based on 100% by weight of the ABS resin.

[0026] The flame-retardant maleimide copolymer containing the above flame-retardant maleimide copolymer or the flame-retardant maleimide copolymer prepared by the above method can be subjected to twin-screw melt extrusion granulation, drying and injection molding to obtain ABS resin modified by the flame-retardant maleimide copolymer.

[0027] Beneficial effects:

[0028] 1. The present invention can solve the contradiction between flame retardancy, heat resistance and mechanical properties of materials, and has good comprehensive performance;

[0029] 2. The present invention can achieve high-efficiency flame retardancy of materials with low phosphorus and nitrogen content.

[0030] 3. The present invention has strong flame retardant efficiency and low combustion toxicity.

[0031] 4. The preparation method of the present invention has mature technology, simple operation, easy control and industrialization, especially the use of a vacuum roller scraper to remove the solvent from the product, with high solvent recovery efficiency, greatly reducing the energy consumption of solvent recovery.

[0032] 5. The flame-retardant maleimide copolymer of the present invention has the advantages of controllable molecular weight and good molecular weight distribution, and good compatibility and processing fluidity with ABS resin. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 It is a comparison diagram of the DSC curves of the flame-retardant maleimide copolymer of Example 1 and the MS-NB sample of Nippon Electric Chemical. DETAILED DESCRIPTION

[0034] In order to achieve the first object of the present invention, the flame retardant maleimide copolymer has the structural formula shown in formula (I):

[0035]

[0036] Wherein, the R can be independently selected from one or more of benzene ring, diphenylmethane, and cyclohexane;

[0037] The value ranges of X, Y, Z, and N are 50 to 200 respectively.

[0038] In a specific embodiment, the number average molecular weight of the flame retardant maleimide copolymer is 30,000 to

[0039] 100000, the polydispersity coefficient is 1.8-2.3, and the glass transition temperature is 190-220℃.

[0040] To achieve the second object of the present invention, the method comprises:

[0041] A. reacting triallyl isocyanurate and 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide to obtain a reactive flame retardant monomer TAIC-DOPO;

[0042] B. The reactive flame retardant monomer TAIC-DOPO is polymerized with styrene, maleic anhydride and maleimide monomers to obtain a flame retardant maleimide copolymer.

[0043] The synthesis equation of step A is as follows:

[0044]

[0045] The synthesis equation of step B is as follows:

[0046]

[0047] In one embodiment of the present invention, the preparation process of the flame retardant monomer is as follows: under N2 atmosphere, sulfolane, 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO, CAS No. 35948-25-5) are added to the reactor, the oil temperature is raised to 140°C, and stirred until DOPO is completely dissolved; then, triallyl triazine trione (TAIC, CAS No. 1025-15-6) is slowly added to the reactor. The oil temperature is then raised to 155°C and reacted for 2 hours. After the reaction is completed, the temperature is lowered and cooled, the product is poured into ethanol for precipitation, and washed several times with deionized water until the supernatant becomes neutral. Finally, the product is vacuum dried at 120°C to obtain a white powdery flame retardant monomer TAIC-DOPO.

[0048] In a specific embodiment, the molar ratio of the maleimide monomer, styrene, maleic anhydride and reactive flame retardant monomer TAIC-DOPO is 10-15:30-35:2-3:0.1-2.

[0049] In a specific embodiment, the reaction in step A comprises mixing a solvent, 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide DOPO and triallyl triazine trione under a protective atmosphere, and reacting at 140-160° C. for 1-3 hours;

[0050] The molar ratio of the 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide to triallyl triazine trione is preferably 2:1.

[0051] In a specific embodiment, the solvent for the polymerization reaction in step A and step B is at least one of tetrahydrofuran, butanone, cyclohexanone, methyl ethyl ketone, methyl isobutyl ketone, 1,4-dioxane, and sulfolane.

[0052] In a specific embodiment, the initiator of the polymerization reaction in step B is at least one of azobisisobutyronitrile, azobisisoheptylnitrile, di-tert-butyl peroxide, diisopropylbenzene peroxide, benzoyl peroxide, cyclohexanone peroxide, tert-butyl perbenzoate, and 1,1-di(tert-butylperoxy)-3,3,5-trimethylcyclohexane.

[0053] In a specific embodiment, the polymerization reaction in step B is heated to 80-100° C. under a protective atmosphere and reacted for 4-8 hours.

[0054] In a specific embodiment, the method further includes step C: after the polymerization reaction is completed, a vacuum roller scraper is used to remove the solvent, wash, and vacuum dry to obtain a flame-retardant maleimide copolymer resin, and the washing solution is preferably at least one of ethanol, methanol, acetone, and chloroform.

[0055] To achieve the third object of the present invention, the ABS resin contains the flame retardant maleimide copolymer or the flame retardant maleimide copolymer prepared by the above method; preferably, the flame retardant maleimide copolymer is added in an amount of 1% to 40% by weight based on 100% by weight of the ABS resin.

[0056] The specific implementation modes of the present invention are further described below in conjunction with embodiments, but the present invention is not limited to the scope of the embodiments.

[0057] Comparative Example 1

[0058] 40 parts of Nippon Electric Chemical heat-resistant ABS modifier (brand: MS-NB) and 100 parts of ABS resin (brand: 0215H) were mixed and extruded and injection molded at 250-275°C to obtain a high-temperature resistant ABS material; the tensile strength was 48.6MPa, the flexural strength was 84.4MPa, the flexural modulus was 2652MPa, and the notched impact strength was 70.8kJ / m 2 , Vicat softening temperature is 113.1℃, flame retardant grade is HB, see Table 1 for details.

[0059] Example 1

[0060] 1) Under nitrogen atmosphere, add 1000mL of sulfolane and 432g (2mol) of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) into a 5000mL reactor with a mechanical stirring device. Place it in an oil bath, raise the oil temperature to 140°C, and stir until DOPO is completely dissolved; then, slowly add 249g (1mol) of triallyl triazine trione (TAIC) into the reactor. Then raise the oil temperature to 155°C and react for 2h. After the reaction is completed, cool down, pour the product into ethanol for precipitation, and wash it with deionized water for several times until the supernatant becomes neutral. Finally, the product is vacuum dried at 120°C to obtain a white powdery flame retardant monomer (TAIC-DOPO).

[0061] 2) Under a nitrogen atmosphere, 2000 g of cyclohexanone, 132 g of TAIC-DOPO, 432.9 g of N-phenylmaleimide, 708.2 g of styrene and 49 g of maleic anhydride were added to a reaction kettle equipped with a condenser and the solvent was stirred, and then 4 g of tert-butyl perbenzoate was added, and the oil temperature was raised to 90° C. for reaction for 6 h; then it was introduced into a vacuum drum scraper to remove the solvent, and then the solid particles were crushed and washed twice with ethanol, and finally dried in a vacuum drying oven at 100° C. for 4 h to obtain a white powdery flame-retardant maleimide copolymer.

[0062] 3) 10 parts of flame-retardant maleimide copolymer and 100 parts of ABS resin (brand: 0215H) were mixed and extruded and injection molded at 250-275°C to obtain a high-temperature resistant flame-retardant ABS material; the tensile strength was 44.7MPa, the flexural strength was 74.9MPa, the flexural modulus was 2535MPa, and the notched impact strength was 86.3kJ / m 2 , Vicat softening temperature is 99°C, and flame retardant grade is HB, see Table 1 for details.

[0063] Example 2

[0064] 1) Under nitrogen atmosphere, 2000 g of cyclohexanone, 132 g of TAIC-DOPO, 432.9 g of N-phenylmaleimide, 708.2 g of styrene and 49 g of maleic anhydride were added to a reaction kettle with a condensing device to stir the solvent, and then 4 g of tert-butyl perbenzoate was added, and the oil temperature was raised to 90° C. for reaction for 6 h; then it was introduced into a vacuum drum scraper to remove the solvent, and then the solid particles were crushed and washed with ethanol twice, and finally dried in a vacuum drying oven at 100° C. for 4 h to obtain a white powdery flame-retardant maleimide copolymer.

[0065] 2) 20 parts of flame-retardant maleimide copolymer and 100 parts of ABS resin (brand: 0215H) were mixed and extruded at 250-275°C and injection molded to obtain a high-temperature resistant flame-retardant ABS material; the tensile strength was 45.8MPa, the flexural strength was 78.7MPa, the flexural modulus was 2565MPa, and the notched impact strength was 81.9kJ / m 2 , Vicat softening temperature is 104.4℃, flame retardant grade is V-2, see Table 1 for details.

[0066] Example 3

[0067] 1) Under nitrogen atmosphere, 2000 g of cyclohexanone, 132 g of TAIC-DOPO, 432.9 g of N-phenylmaleimide, 708.2 g of styrene and 49 g of maleic anhydride were added to a reaction kettle with a condensing device to stir the solvent, and then 4 g of tert-butyl perbenzoate was added, and the oil temperature was raised to 90° C. for reaction for 6 h; then it was introduced into a vacuum drum scraper to remove the solvent, and then the solid particles were crushed and washed with ethanol twice, and finally dried in a vacuum drying oven at 100° C. for 4 h to obtain a white powdery flame-retardant maleimide copolymer.

[0068] 2) 30 parts of flame-retardant maleimide copolymer and 100 parts of ABS resin (brand: 0215H) were mixed and extruded at 250-275°C and injection molded to obtain a high-temperature resistant flame-retardant ABS material; the tensile strength was 46.9MPa, the flexural strength was 81.4MPa, the flexural modulus was 2660MPa, and the notched impact strength was 76.5kJ / m2 , Vicat softening temperature is 106.8℃, flame retardant grade is V-1, see Table 1 for details.

[0069] Example 4

[0070] 1) Under nitrogen atmosphere, 2000 g of cyclohexanone, 132 g of TAIC-DOPO, 432.9 g of N-phenylmaleimide, 708.2 g of styrene and 49 g of maleic anhydride were added to a reaction kettle with a condensing device to stir the solvent, and then 4 g of tert-butyl perbenzoate was added, and the oil temperature was raised to 90° C. for reaction for 6 h; then it was introduced into a vacuum drum scraper to remove the solvent, and then the solid particles were crushed and washed with ethanol twice, and finally dried in a vacuum drying oven at 100° C. for 4 h to obtain a white powdery flame-retardant maleimide copolymer.

[0071] 2) 40 parts of flame-retardant maleimide copolymer and 100 parts of ABS resin (brand: 0215H) were mixed and extruded at 250-275°C and injection molded to obtain a high-temperature resistant flame-retardant ABS material; the tensile strength was 49.1MPa, the flexural strength was 85.5MPa, the flexural modulus was 2782MPa, and the notched impact strength was 71.2kJ / m 2 , Vicat softening temperature is 113.4℃, flame retardant grade is V-0, see Table 1 for details.

[0072] Example 5

[0073] 1) Under a nitrogen atmosphere, 1900 g of cyclohexanone, 62.6 g of TAIC-DOPO, 432.9 g of N-phenylmaleimide, 708.2 g of styrene and 49 g of maleic anhydride were added to a reaction kettle with a condensing device to stir the solvent, and then 3.76 g of tert-butyl perbenzoate was added, and the oil temperature was raised to 90° C. for reaction for 6 hours; then it was introduced into a vacuum roller scraper to remove the solvent, and then the solid particles were crushed and washed with ethanol twice, and finally dried in a vacuum drying oven at 100° C. for 4 hours to obtain a white powdery flame-retardant maleimide copolymer.

[0074] 2) 40 parts of flame-retardant maleimide copolymer and 100 parts of ABS resin (brand: 0215H) were mixed and extruded at 250-275°C and injection molded to obtain a high-temperature resistant flame-retardant ABS material; the tensile strength was 48.7MPa, the flexural strength was 84.6MPa, the flexural modulus was 2682MPa, and the notched impact strength was 74.3kJ / m 2 , Vicat softening temperature is 112.9℃, flame retardant grade is V-1, see Table 1 for details.

[0075] Example 6

[0076] 1) Under a nitrogen atmosphere, 2100 g of cyclohexanone, 210 g of TAIC-DOPO, 432.9 g of N-phenylmaleimide, 708.2 g of styrene and 49 g of maleic anhydride were added to a reaction kettle equipped with a condenser and the solvent was stirred, and then 4.2 g of tert-butyl perbenzoate was added, and the oil temperature was raised to 90° C. for reaction for 6 hours; then it was introduced into a vacuum drum scraper to remove the solvent, and then the solid particles were crushed and washed with ethanol twice, and finally dried in a vacuum drying oven at 100° C. for 4 hours to obtain a white powdery flame-retardant maleimide copolymer.

[0077] 2) 40 parts of flame-retardant maleimide copolymer and 100 parts of ABS resin (brand: 0215H) were mixed and extruded at 250-275°C and injection molded to obtain a high-temperature resistant flame-retardant ABS material; the tensile strength was 47.8MPa, the flexural strength was 86.6MPa, the flexural modulus was 2872MPa, and the notched impact strength was 66kJ / m 2 , Vicat softening temperature is 114.6℃, flame retardant grade is V-0, see Table 1 for details.

[0078] Table 1 ABS material performance test table

[0079]

Claims

1. A flame retardant maleimide copolymer, characterized in that: The structural formula of the flame retardant maleimide copolymer is shown in formula (I): Wherein, the R can be independently selected from one or more of benzene ring, diphenylmethane, and cyclohexane; The value ranges of X, Y, Z, and N are 50 to 200 respectively.

2. The method for preparing the flame-retardant maleimide copolymer according to claim 1, characterized in that: The flame-retardant maleimide copolymer has a number average molecular weight of 30,000 to 100,000, a polydispersity coefficient of 1.8 to 2.3, and a glass transition temperature of 190 to 220°C.

3. The method for preparing a flame-retardant maleimide-based copolymer according to claim 1 or 2, characterized in that: The method comprises: A. reacting triallyl isocyanurate and 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide to obtain a reactive flame retardant monomer TAIC-DOPO; B. The reactive flame retardant monomer TAIC-DOPO is polymerized with styrene, maleic anhydride and maleimide monomers to obtain a flame retardant maleimide copolymer.

4. The method for preparing the flame-retardant maleimide copolymer according to claim 3, characterized in that: The molar ratio of the maleimide monomer, styrene, maleic anhydride and reactive flame retardant monomer TAIC-DOPO is 10-15:30-35:2-3:0.1-2.

5. The method for preparing the flame-retardant maleimide copolymer according to claim 3, characterized in that: The reaction in step A comprises mixing a solvent, 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide DOPO and triallyl triazine trione under a protective atmosphere, and reacting at 140-160° C. for 1-3 hours; The molar ratio of the 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide to triallyl triazine trione is preferably 2:

1.

6. The method for preparing the flame-retardant maleimide copolymer according to claim 3, characterized in that: The solvents for the polymerization reactions in step A and step B are at least one of tetrahydrofuran, butanone, cyclohexanone, methyl ethyl ketone, methyl isobutyl ketone, 1,4-dioxane and sulfolane.

7. The method for preparing the flame-retardant maleimide copolymer according to claim 3, characterized in that: The initiator of the polymerization reaction in step B is at least one of azobisisobutyronitrile, azobisisoheptylnitrile, di-tert-butyl peroxide, diisopropylbenzene peroxide, benzoyl peroxide, cyclohexanone peroxide, tert-butyl perbenzoate, and 1,1-di(tert-butylperoxy)-3,3,5-trimethylcyclohexane.

8. The method for preparing the flame-retardant maleimide copolymer according to claim 3, characterized in that: In step B, the polymerization reaction is heated to 80-100° C. under a protective atmosphere and reacted for 4-8 hours.

9. The method for preparing the flame-retardant maleimide copolymer according to claim 3, characterized in that: The method further comprises step C: after the polymerization reaction is completed, a vacuum roller scraper is used to remove the solvent, wash, and vacuum dry to obtain a flame-retardant maleimide copolymer resin, wherein the washing solution is preferably at least one of ethanol, methanol, acetone, and chloroform.

10. Flame-retardant maleimide copolymer-modified ABS resin, characterized in that: The ABS resin contains the flame-retardant maleimide copolymer described in claims 1 to 2 or the flame-retardant maleimide copolymer prepared by the method described in any one of claims 3 to 9; preferably, the added weight of the flame-retardant maleimide copolymer is 1% to 40% based on 100% by weight of the ABS resin.

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