A kind of anti-aging unsaturated polyester and preparation method thereof

Abstract

The invention discloses an anti-aging unsaturated polyester and a preparation method thereof, and relates to the technical field of anti-aging polyester. The preparation method comprises the following steps: step 1: preparing triol triazine; step 2: (1) adding part of diol, part of saturated dibasic acid or anhydride, part of unsaturated dibasic acid or anhydride, catalyst, and part of polymerization inhibitor to a reaction system in sequence, and reacting for a period of time; (2) cooling the reaction system, adding triol triazine, the remaining part of diol, the remaining part of saturated dibasic acid or anhydride, and the remaining part of unsaturated dibasic acid or anhydride, and continuing to react for a period of time to obtain an unsaturated polyester prepolymer; (3) cooling the reaction system, adding a diluent, a flame retardant, and a polymerization inhibitor, stirring for a period of time, vacuuming, and discharging to obtain an anti-aging unsaturated polyester. The prepared anti-aging unsaturated polyester has good 3D printing properties, excellent mechanical properties, anti-aging properties, and flame retardancy.

Description

Technical Field

[0001] The invention relates to the technical field of anti-aging polyester, in particular to an anti-aging unsaturated polyester and a preparation method thereof. Background Art

[0002] Unsaturated polyester is a photo- or thermosetting material with wide application potential in the field of 3D printing technology. It is mainly composed of unsaturated prepolymers and vinyl diluents, and uses its unsaturated double bonds to quickly form during light or heat curing. However, it usually contains benzene rings and double bonds, which makes the unsaturated polyester curing molding material oxidized and yellowed during long-term use, affecting the reliability and aesthetics of the product. Therefore, it is of great significance to solve the anti-aging property of unsaturated polyester.

[0003] In the prior art, the method to improve its aging resistance is usually to introduce functional additives such as nanomaterials and anti-ultraviolet agents; at the same time, in order to solve the defect of unsaturated polyester being easy to burn, flame retardants are usually introduced as functional additives. However, the introduction of relevant functional additives has the following problems: first, poor compatibility reduces the functional efficiency of the functional additives; second, there are migration or agglomeration problems, which will damage the mechanical properties; third, the introduction of functional additives increases the viscosity of the unsaturated resin, affecting the flow properties, thereby reducing its 3D printing efficiency, and incomplete curing under common curing conditions. Instead, there are too many unreacted groups, which leads to reduced mechanical properties and functionality.

[0004] In summary, it is of great significance to solve the above problems and prepare an anti-aging unsaturated polyester. Summary of the invention

[0005] The object of the present invention is to provide an anti-aging unsaturated polyester and a preparation method thereof, so as to solve the problems raised in the prior art.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] A method for preparing an anti-aging unsaturated polyester comprises the following steps:

[0008] Step 1: Add 1,3,5-trialdehyde-1,3,5-triazine to ethyl acetate, dropwise add ethyl acetate solution containing 2-[2-(2-aminoethoxy)ethoxy]ethanol, stir and react at 65-70° C. for 4-5 hours; evaporate the solvent to obtain triol triazine;

[0009] Step 2: (1) Add part of the diol, part of the saturated dibasic acid or anhydride, part of the unsaturated dibasic acid or anhydride, the catalyst, and part of the polymerization inhibitor to the reaction system in sequence, stir at 120-140°C for 30-40 minutes, heat to 170-180°C, and react until the acid value is 20-28 mgKOH / g; (2) Cool the reaction system to 100-120°C, add triol triazine, the remaining part of the diol, the remaining part of the saturated dibasic acid or anhydride, and the remaining part of the unsaturated dibasic acid or anhydride, stir at 140-160°C for 10-15 minutes, heat to 180-200°C, and react until the acid value is 15-20 mgKOH / g; obtain an unsaturated polyester prepolymer; (3) Cool the reaction system to 100-120°C, add a diluent, a flame retardant, and a polymerization inhibitor, stir for 1.5-3 hours, evacuate, and discharge to obtain an anti-aging unsaturated polyester.

[0010] More optimally, the anti-aging unsaturated polyester includes the following component raw materials: by weight, 18 to 20 parts of diols, 10 to 14 parts of saturated dibasic acids or acid anhydrides, 18 to 22 parts of unsaturated dibasic acids or acid anhydrides, 0.05 to 0.1 parts of catalysts, 0.05 to 0.1 parts of inhibitors, 10 to 12 parts of triol triazines, 34 to 42 parts of diluents, and 14 to 18 parts of flame retardants.

[0011] More optimally, in the raw materials of the triol triazine, the molar ratio of 1,3,5-trialdehyde-1,3,5-triazine and 2-[2-(2-aminoethoxy)ethoxy]ethanol is 1:3.05~3.15.

[0012] More optimally, the diluent includes an isosorbide diluent and a triazine diluent in a mass ratio of 6.5-7:1-1.5.

[0013] More optimally, the preparation method of the isosorbide diluent is: adding isosorbide and 4-dimethylaminopyridine to dichloromethane, adding methacrylic anhydride at room temperature, reacting at 60-65° C. for 24 hours, and purifying to obtain the isosorbide diluent;

[0014] The preparation method of the triazine-based diluent is as follows: adding triol triazine and 4-dimethylamino pyridine to dichloromethane, adding methacrylic anhydride at room temperature, reacting at 60-65° C. for 24 hours, and purifying to obtain the triazine-based diluent.

[0015] More optimally, the mass ratio of isosorbide to methacrylic anhydride in the isosorbide diluent is 1.5:3.5-4; the mass ratio of triol triazine to methacrylic anhydride is 6:5-5.5.

[0016] More optimally, the preparation method of the flame retardant is as follows: (1) adding 2,4-diamino-6-vinyl-S-triazine to ethyl acetate and dispersing it evenly to obtain solution A; (2) adding terephthalaldehyde and 1,4-pyrazinedicarboxaldehyde to ethyl acetate and dispersing it evenly; adding ammonium polyphosphate, stirring evenly, adding solution A dropwise, heating to 65-70°C, stirring until the solvent is completely evaporated, and drying the product to obtain a flame retardant.

[0017] More optimally, the raw materials of the flame retardant include the following raw materials in parts by weight: 48 to 50 parts of ammonium polyphosphate, 14 to 16 parts of 2,4-diamino-6-vinyl-S-triazine, 3 to 4 parts of 1,4-pyrazine dicarboxaldehyde, and 5 to 6 parts of terephthalaldehyde.

[0018] More optimally, the diol includes one or more of pentanediol, propylene glycol, and butanediol; the saturated dibasic acid or anhydride includes one or more of isophthalic acid, phthalic anhydride, adipic acid, glutaric acid, and glutaric anhydride; the unsaturated dibasic acid or anhydride includes one or more of itaconic acid, itaconic anhydride, and maleic anhydride.

[0019] Compared with the prior art, the beneficial effects of the present application are as follows: triol triazine is introduced into the anti-aging unsaturated polyester as a branching agent and an anti-aging agent, and 2,4-diamino-6-vinyl-S-triazine modified ammonium polyphosphate with similar chain segments is used as a flame retardant; and a triazine-based diluent is prepared using triol triazine as a diluent; based on this, the mechanical properties, anti-aging and flame retardancy of the unsaturated polyester are effectively enhanced while ensuring that the unsaturated polyester can be 3D printed based on the triazine compound.

[0020] Among them, 1,3,5-trialdehyde-1,3,5-triazine is used as the base, and the reaction between aldehyde group and amino group is used to react it with 2-[2-(2-aminoethoxy)ethoxy]ethanol to obtain a triol triazine containing a three-arm chain; and it is introduced into the unsaturated polyester; first, as a branching agent, it has branching properties and has a toughening ether-containing segment, so its introduction can reduce the shrinkage stress in the photocuring 3D printing technology, improve the printing quality, and improve the mechanical properties of the material. Second, as an anti-aging agent, it has a reactive alcohol group and a oxazine group with ultraviolet light absorption performance, so its introduction has reaction compatibility and can be condensed in the prepolymer segment of the unsaturated polyester, effectively enhancing its compatibility. Third, the introduction time is after a period of polycondensation, and the introduction amount is limited, the purpose is to avoid destroying the polycondensation uniformity of the unsaturated polyester, affecting the cross-linking of the thickness photocuring, and affecting its mechanical properties.

[0021] Among them, in order to avoid reducing the prepolymerization uniformity of the polymerization prepolymer, the scheme limits the amount of triol triazine introduced; in order to further enhance the anti-aging property of the anti-aging unsaturated polyester, the scheme further uses triol triazine as a basis and reacts with methacrylic anhydride to prepare a triazine-based diluent. Using it as a diluent, first, it can be used as a cross-linking agent to increase the cross-linking degree of the unsaturated polyester, improve the formability and mechanical properties. On the other hand, it further improves the anti-aging property, and at the same time, it has similar compatibility with the prepolymer of the unsaturated polyester, which can enhance the fluidity of the unsaturated polyester and reduce the viscosity; and ensure 3D printing.

[0022] At the same time, the triazine-based diluent is only used as an auxiliary, and the diluent is mainly composed of isosorbide diluent. It is a bio-based diluent, and its introduction alone has little effect on flame retardancy. However, under the flame retardant premise of phosphorus-containing ammonium polyphosphate in this application, compared with the common styrene as a diluent, isosorbide diluent has a lower heat release rate, and its synergistic ammonium polyphosphate has better flame retardancy. However, since the reactivity of isosorbide diluent is lower than that of styrene diluent, it will affect the mechanical properties of the material, so the triazine-based diluent is introduced as a cross-linking agent in the scheme to improve the reaction cross-linking.

[0023] Among them, in the scheme, in order to improve the compatibility of the flame retardant ammonium polyphosphate with unsaturated polyester prepolymers, the scheme uses a Schiff base reaction between 2,4-diamino-6-vinyl-S-triazine, terephthalaldehyde, and 1,4-pyrazinedicarboxaldehyde to modify the ammonium polyphosphate, thereby utilizing its similar compatibility with the unsaturated polyester prepolymer chain segment and the reaction compatibility of the vinyl contained therein, effectively enhancing its compatibility while further enhancing its aging resistance and flame retardancy. DETAILED DESCRIPTION

[0024] Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in the field without making any creative work shall fall within the scope of protection of the present invention.

[0025] It should be noted that the purchase manufacturers of all raw materials involved in the present invention are exemplified without any special restrictions: in the following embodiments, parts are by mass; the CAS number of 2-[2-(2-aminoethoxy)ethoxy]ethanol is 6338-55-2, the CAS number of 1,3,5-trialdehyde-1,3,5-triazine and isosorbide is 652-67-5, the CAS number of 2,4-diamino-6-vinyl-S-triazine is 3194-70-5, the CAS number of 1,4-pyrazinedicarboxaldehyde is 4164-39-0, and the CAS number of terephthalaldehyde is 623-27-8; ammonium polyphosphate is purchased from Shandong Suihua Biotechnology Co., Ltd.; all raw materials are commercially purchased.

[0026] Embodiment 1: A method for preparing an anti-aging unsaturated polyester comprises the following steps:

[0027] Step 1: S1.1: Weigh 1,3,5-trialdehyde-1,3,5-triazine and 2-[2-(2-aminoethoxy)ethoxy]ethanol in a molar ratio of 1:3.1; add 1,3,5-trialdehyde-1,3,5-triazine to ethyl acetate, dropwise add ethyl acetate solution containing 2-[2-(2-aminoethoxy)ethoxy]ethanol, and stir at 70° C. for 4 hours to react; evaporate the solvent to obtain triol triazine;

[0028] S1.2: (1) Add 1.5 parts of isosorbide and 0.1 parts of 4-dimethylaminopyridine to dichloromethane, add 3.8 parts of methacrylic anhydride at room temperature, react at 60°C for 24 hours, purify, and obtain isosorbide diluent; (2) Add 6 parts of triol triazine and 0.15 parts of 4-dimethylaminopyridine to dichloromethane, add 5.4 parts of methacrylic anhydride at room temperature, react at 60°C for 24 hours, purify, and obtain triazine diluent; (3) Mix isosorbide diluent and triazine diluent in a mass ratio of 7:1 to obtain diluent;

[0029] S1.3: (1) Add 15 parts of 2,4-diamino-6-vinyl-S-triazine to 100 parts of ethyl acetate and disperse them evenly to obtain solution A; (2) Add 5.5 parts of terephthalaldehyde and 3.5 parts of 1,4-pyrazine dicarboxaldehyde to 150 parts of ethyl acetate and disperse them evenly; add 50 parts of ammonium polyphosphate, stir evenly, add solution A dropwise, heat to 65°C, stir until the solvent is completely evaporated, and dry the product at 80°C to obtain a flame retardant;

[0030] Step 2: (1) 1,2-neopentyl glycol, 6 parts of isophthalic acid, 10 parts of maleic anhydride, 0.09 parts of p-toluenesulfonic acid, and 0.08 parts of 4-methoxyphenol were added to the reaction system in sequence, stirred at 140°C for 30 minutes, heated to 180°C at a rate of 10°C / min, and reacted until the acid value reached 25 mgKOH / g; (2) the reaction system was cooled to 110°C, 10 parts of triol triazine, 6 parts of neopentyl glycol, 2 parts of isophthalic acid, and 4 parts of Adipic acid, 5 parts of maleic anhydride and 5 parts of itaconic anhydride are stirred at 160°C for 10 minutes, heated to 200°C at a rate of 10°C / min, and reacted until the acid value reaches 20 mgKOH / g; an unsaturated polyester prepolymer is obtained; (3) the reaction system is cooled to 120°C, 40 parts of a diluent, 16 parts of a flame retardant, 0.01 parts of tetrabutyl orthotitanate and 0.02 parts of 4-methoxyphenol are added, stirred for 2 hours, vacuumized, and discharged to obtain an anti-aging unsaturated polyester.

[0031] Embodiment 2: A method for preparing an anti-aging unsaturated polyester comprises the following steps:

[0032] Step 1: S1.1: Weigh 1,3,5-trialdehyde-1,3,5-triazine and 2-[2-(2-aminoethoxy)ethoxy]ethanol in a molar ratio of 1:3.1; add 1,3,5-trialdehyde-1,3,5-triazine to ethyl acetate, dropwise add ethyl acetate solution containing 2-[2-(2-aminoethoxy)ethoxy]ethanol, and stir at 70° C. for 4 hours to react; evaporate the solvent to obtain triol triazine;

[0033] S1.2: (1) Add 1.5 parts of isosorbide and 0.1 parts of 4-dimethylaminopyridine to dichloromethane, add 3.8 parts of methacrylic anhydride at room temperature, react at 60°C for 24 hours, purify, and obtain isosorbide diluent; (2) Add 6 parts of triol triazine and 0.15 parts of 4-dimethylaminopyridine to dichloromethane, add 5.4 parts of methacrylic anhydride at room temperature, react at 60°C for 24 hours, purify, and obtain triazine diluent; (3) Mix isosorbide diluent and triazine diluent in a mass ratio of 7:1 to obtain diluent;

[0034] S1.3: (1) Add 15 parts of 2,4-diamino-6-vinyl-S-triazine to 100 parts of ethyl acetate and disperse them evenly to obtain solution A; (2) Add 5.5 parts of terephthalaldehyde and 3.5 parts of 1,4-pyrazine dicarboxaldehyde to 150 parts of ethyl acetate and disperse them evenly; add 50 parts of ammonium polyphosphate, stir evenly, add solution A dropwise, heat to 65°C, stir until the solvent is completely evaporated, and dry the product at 80°C to obtain a flame retardant;

[0035] Step 2: (1) 12 parts of neopentyl glycol, 5 parts of isophthalic acid, 10 parts of maleic anhydride, 0.09 parts of p-toluenesulfonic acid, and 0.08 parts of 4-methoxyphenol are added to the reaction system in sequence, stirred at 140°C for 30 minutes, heated to 180°C at a rate of 10°C / min, and reacted until the acid value reaches 25 mgKOH / g; (2) the reaction system is cooled to 110°C, 10 parts of triol triazine, 6 parts of neopentyl glycol, 2 parts of isophthalic acid, and 3 parts of Adipic acid, 4 parts of maleic anhydride and 4 parts of itaconic anhydride are stirred at 160°C for 10 minutes, heated to 200°C at a rate of 10°C / min, and reacted until the acid value reaches 20 mgKOH / g; an unsaturated polyester prepolymer is obtained; (3) the reaction system is cooled to 120°C, 34 parts of a diluent, 14 parts of a flame retardant, 0.01 parts of tetrabutyl orthotitanate and 0.02 parts of 4-methoxyphenol are added, stirred for 2 hours, vacuumized, and discharged to obtain an anti-aging unsaturated polyester.

[0036] Embodiment 3: A method for preparing an anti-aging unsaturated polyester comprises the following steps:

[0037] Step 1: S1.1: Weigh 1,3,5-trialdehyde-1,3,5-triazine and 2-[2-(2-aminoethoxy)ethoxy]ethanol in a molar ratio of 1:3.1; add 1,3,5-trialdehyde-1,3,5-triazine to ethyl acetate, dropwise add ethyl acetate solution containing 2-[2-(2-aminoethoxy)ethoxy]ethanol, and stir at 70° C. for 4 hours to react; evaporate the solvent to obtain triol triazine;

[0038] S1.2: (1) Add 1.5 parts of isosorbide and 0.1 parts of 4-dimethylaminopyridine to dichloromethane, add 3.8 parts of methacrylic anhydride at room temperature, react at 60°C for 24 hours, purify, and obtain isosorbide diluent; (2) Add 6 parts of triol triazine and 0.15 parts of 4-dimethylaminopyridine to dichloromethane, add 5.4 parts of methacrylic anhydride at room temperature, react at 60°C for 24 hours, purify, and obtain triazine diluent; (3) Mix isosorbide diluent and triazine diluent in a mass ratio of 7:1 to obtain diluent;

[0039] S1.3: (1) Add 15 parts of 2,4-diamino-6-vinyl-S-triazine to 100 parts of ethyl acetate and disperse them evenly to obtain solution A; (2) Add 5.5 parts of terephthalaldehyde and 3.5 parts of 1,4-pyrazine dicarboxaldehyde to 150 parts of ethyl acetate and disperse them evenly; add 50 parts of ammonium polyphosphate, stir evenly, add solution A dropwise, heat to 65°C, stir until the solvent is completely evaporated, and dry the product at 80°C to obtain a flame retardant;

[0040] Step 2: (1) 12 parts of neopentyl glycol, 6 parts of isophthalic acid, 10 parts of maleic anhydride, 0.09 parts of p-toluenesulfonic acid and 0.08 parts of 4-methoxyphenol were added to the reaction system in sequence, stirred at 140°C for 30 minutes, heated to 180°C at a rate of 10°C / min, and reacted until the acid value reached 25 mgKOH / g; (2) the reaction system was cooled to 110°C, 12 parts of triol triazine, 8 parts of neopentyl glycol, 4 parts of isophthalic acid and 4 parts of Adipic acid, 6 parts of maleic anhydride and 6 parts of itaconic anhydride are stirred at 160°C for 10 minutes, heated to 200°C at a rate of 10°C / min, and reacted until the acid value reaches 20 mgKOH / g; an unsaturated polyester prepolymer is obtained; (3) the reaction system is cooled to 120°C, 42 parts of a diluent, 18 parts of a flame retardant, 0.01 parts of tetrabutyl orthotitanate and 0.02 parts of 4-methoxyphenol are added, stirred for 2 hours, vacuumized, and discharged to obtain an anti-aging unsaturated polyester.

[0041] Comparative Example 1: The position and amount of triol triazine introduced into the unsaturated polyester prepolymer were changed, and the rest was the same as Example 1; the specific changes were as follows:

[0042] Step 2: (1) 10 parts of neopentyl glycol, 6 parts of isophthalic acid, 15 parts of triol triazine, 10 parts of maleic anhydride, 0.09 parts of p-toluenesulfonic acid, and 0.08 parts of 4-methoxyphenol are added to the reaction system in sequence, stirred at 140°C for 30 minutes, heated to 180°C at a rate of 10°C / min, and reacted until the acid value reaches 25 mgKOH / g; (2) the reaction system is cooled to 110°C, 3 parts of neopentyl glycol, 2 parts of isophthalic acid and 4 parts of Adipic acid, 5 parts of maleic anhydride and 5 parts of itaconic anhydride are stirred at 160°C for 10 minutes, heated to 200°C at a rate of 10°C / min, and reacted until the acid value reaches 20 mgKOH / g; an unsaturated polyester prepolymer is obtained; (3) the reaction system is cooled to 120°C, 40 parts of a diluent, 16 parts of a flame retardant, 0.01 parts of tetrabutyl orthotitanate and 0.02 parts of 4-methoxyphenol are added, stirred for 2 hours, vacuumized, and discharged to obtain an anti-aging unsaturated polyester.

[0043] Comparative Example 2: In the flame retardant, 2,4-diamino-6-vinyl-S-triazine was replaced with 1,2-bis(2-aminoethoxy)ethane, and the rest was the same as Example 1; the specific changes were as follows:

[0044] S1.3: (1) Add 7.5 parts of 1,2-bis(2-aminoethoxy)ethane to 100 parts of ethyl acetate and disperse them evenly to obtain solution A; (2) Add 6.5 parts of terephthalaldehyde to 150 parts of ethyl acetate and disperse them evenly; add 50 parts of ammonium polyphosphate, stir evenly, add solution A dropwise, heat to 65°C, stir until the solvent is completely evaporated, and dry the product at 80°C to obtain a flame retardant;

[0045] Comparative Example 3: Using a single sorbitol diluent as the diluent, the rest is the same as Example 1.

[0046] Comparative Example 4: Styrene was used as the diluent; the rest was the same as Example 1.

[0047] Performance test: The anti-aging unsaturated polyester prepared in the embodiment and the comparative example was mixed with 2wt% methyl ethyl ketone peroxide (accounting for 2wt% of the anti-aging unsaturated polyester), 0.5wt% cobalt isooctanoate (accounting for 0.5wt% of the anti-aging unsaturated polyester), and 1173 initiator (accounting for 1wt% of the anti-aging unsaturated polyester), and printed under ultraviolet light at a temperature of 120°C. After molding, it was cured at 140°C for 1 hour to obtain a polyester material; the polyester material was subjected to relevant performance tests, one of which was 130×6.5×3mm 3First, the limiting oxygen index test was carried out; second, the tensile performance test was carried out at a tensile rate of 2mm / min to obtain the tensile strength; third, the tensile strength was tested again under a UV light source with a power of 400W and a lighting distance of 5cm for 20 days, and the decline rate was obtained by calculation. The obtained data are shown in the following table:

[0048]

[0049] Conclusion: From the data of Example 1, it can be seen that an anti-aging unsaturated polyester with excellent aging resistance, flame retardancy and good printability is prepared in this application. From the data of Comparative Examples 1 to 4, it can be seen that in Comparative Example 1, the introduction position and amount of triol triazine are related to the uniformity of the homopolymer segment, which affects the mechanical properties; the 2,4-diamino-6-vinyl-S-triazine introduced into the flame retardant in Comparative Example 2 affects the similarity and reaction compatibility with the unsaturated polyester prepolymer, affects the crosslinking and interfacial properties, and thus affects the overall performance. On the other hand, the diluent used affects the crosslinking and flame retardancy, so when a single sorbitol diluent is used in Comparative Example 3, the mechanical properties decrease; and when styrene is used as a diluent, the flame retardancy and anti-aging properties decrease.

[0050] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or replace some of the technical features therein by equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for preparing an anti-aging unsaturated polyester, characterized in that: The following steps are involved: Step 1: Add 1,3,5-trialdehyde-1,3,5-triazine to ethyl acetate, dropwise add ethyl acetate solution containing 2-[2-(2-aminoethoxy)ethoxy]ethanol, stir and react at 65-70° C. for 4-5 hours; evaporate the solvent to obtain triol triazine; Step 2: (1) adding part of the diol, part of the saturated dibasic acid or anhydride, part of the unsaturated dibasic acid or anhydride, a catalyst, and part of the polymerization inhibitor to the reaction system in sequence, stirring at 120-140°C for 30-40 minutes, heating to 170-180°C, and reacting until the acid value reaches 20-28 mgKOH / g; (2) cooling the reaction system to 100-120°C, adding triol triazine, the remaining part of the diol, the remaining part of the saturated dibasic acid or anhydride, and the remaining part of the unsaturated dibasic acid or anhydride, stirring at 140-160°C for 10-15 minutes, heating to 180-200°C, and reacting until the acid value reaches 15-20 mgKOH / g; obtaining an unsaturated polyester prepolymer; (3) cooling the reaction system to 100-120°C, adding a diluent, a flame retardant, and a polymerization inhibitor, stirring for 1.5-3 hours, evacuating, and discharging to obtain an anti-aging unsaturated polyester; The diluent includes an isosorbide diluent and a triazine diluent in a mass ratio of 6.5-7:1-1.5; The preparation method of the isosorbide diluent is as follows: adding isosorbide and 4-dimethylaminopyridine to dichloromethane, adding methacrylic anhydride at room temperature, reacting at 60-65° C. for 24 hours, and purifying to obtain the isosorbide diluent; The preparation method of the triazine-based diluent is as follows: adding triol triazine and 4-dimethylamino pyridine to dichloromethane, adding methacrylic anhydride at room temperature, reacting at 60-65° C. for 24 hours, and purifying to obtain the triazine-based diluent; The preparation method of the flame retardant comprises the following steps: (1) adding 2,4-diamino-6-vinyl-S-triazine to ethyl acetate and dispersing the mixture evenly to obtain solution A; (2) adding terephthalaldehyde and 1,4-pyrazinedicarboxaldehyde to ethyl acetate and dispersing the mixture evenly; adding ammonium polyphosphate, stirring the mixture evenly, adding solution A dropwise, heating the mixture to 65-70° C., stirring the mixture until the solvent is completely evaporated, and drying the product to obtain the flame retardant.

2. The method for preparing an anti-aging unsaturated polyester according to claim 1, characterized in that: The anti-aging unsaturated polyester comprises the following raw materials: by weight, 18 to 20 parts of diols, 10 to 14 parts of saturated dibasic acids or acid anhydrides, 18 to 22 parts of unsaturated dibasic acids or acid anhydrides, 0.05 to 0.1 parts of catalysts, 0.05 to 0.1 parts of inhibitors, 10 to 12 parts of triol-based triazines, 34 to 42 parts of diluents, and 14 to 18 parts of flame retardants.

3. The method for preparing an anti-aging unsaturated polyester according to claim 1, characterized in that: In the raw materials of the triol triazine, the molar ratio of 1,3,5-trialdehyde-1,3,5-triazine to 2-[2-(2-aminoethoxy)ethoxy]ethanol is 1:3.05-3.

15.

4. The method for preparing an anti-aging unsaturated polyester according to claim 1, characterized in that: The mass ratio of isosorbide to methacrylic anhydride in the isosorbide diluent is 1.5:3.5-4; the mass ratio of triol triazine to methacrylic anhydride is 6:5-5.

5.

5. The method for preparing an anti-aging unsaturated polyester according to claim 1, characterized in that: The raw materials of the flame retardant include the following raw materials in parts by weight: 48 to 50 parts of ammonium polyphosphate, 14 to 16 parts of 2,4-diamino-6-vinyl-S-triazine, 3 to 4 parts of 1,4-pyrazine dicarboxaldehyde, and 5 to 6 parts of terephthalaldehyde.

6. The anti-aging unsaturated polyester prepared according to the preparation method of an anti-aging unsaturated polyester according to any one of claims 1 to 5.

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