Low-yellowing ultraviolet-resistant epoxy resin composition and preparation method thereof

Abstract

The invention discloses a low-yellowing ultraviolet-resistant epoxy resin composition and a preparation method thereof, and relates to the technical field of composite materials, and the low-yellowing ultraviolet-resistant epoxy resin composition comprises the following components: 50-60 parts of solid epoxy resin, 10-40 parts of liquid epoxy resin, 0.1-5 parts of a UV absorbent, 0.1-5 parts of a heat stabilizer, 3-10 parts of dicyandiamide, 3-10 parts of an accelerant and 0.01-1 part of an auxiliary agent. The preparation method comprises the following steps: pouring the solid epoxy resin and the liquid epoxy resin into a stirring tank, stirring at 100 DEG C until the epoxy resin is molten, cooling to 65 DEG C, adding the UV absorbent and the heat stabilizer, and uniformly stirring to prepare the component A; dicyandiamide, an accelerant, liquid epoxy resin and an auxiliary agent are additionally stirred and subjected to three-axis grinding to serve as a component B; according to the low-yellowing ultraviolet-resistant epoxy resin composition and the preparation method thereof, a certain low-yellowing curing effect can still be achieved by adding a stabilizer into common latent curing agents such as dicyandiamide and organic urea.

Description

Technical Field

[0001] The invention relates to the technical field of composite materials, in particular to a low-yellowing ultraviolet-resistant epoxy resin composition and a preparation method thereof. Background Art

[0002] For specific types of composite materials such as appearance parts, in many application scenarios, appearance parts are often directly exposed to the natural environment, and are subjected to long-term ultraviolet radiation and various complex environmental factors. Therefore, there are extremely stringent requirements for yellowing and UV resistance.

[0003] The existing epoxy resin composition bisphenol A epoxy resin has poor yellowing resistance and UV resistance, aliphatic and cycloaliphatic epoxy resins have high costs, and their mechanical properties are quite different from bisphenol A epoxy resins, and they are prone to yellowing after curing with organic urea accelerators. Therefore, a low-yellowing UV-resistant epoxy resin composition and a preparation method thereof are proposed. Summary of the invention

[0004] In view of the deficiencies in the prior art, the present invention provides a low-yellowing UV-resistant epoxy resin composition and a preparation method thereof, which solves the problem that the organic urea accelerator mentioned in the above background technology is prone to yellowing after curing.

[0005] To achieve the above object, the present invention is implemented by the following technical scheme: a low-yellowing UV-resistant epoxy resin composition, the proportion of which is as follows: 50-60 parts of solid epoxy resin, 10-40 parts of liquid epoxy resin, 0.1-5 parts of UV absorber, 0.1-5 parts of heat stabilizer, 3-10 parts of dicyandiamide, 3-10 parts of accelerator, and 0.01-1 parts of auxiliary agent;

[0006] The preparation method is as follows: pour solid epoxy resin and liquid epoxy resin into a stirring tank, stir at 100°C until melted, then cool to 65°C, add UV absorber and heat stabilizer and stir evenly to prepare component A;

[0007] Dicyandiamide, accelerator, liquid epoxy resin, and auxiliary agent are separately stirred and three-axis ground to form component B;

[0008] Add component B to component A, stir for 30 minutes and then divide into portions and freeze overnight.

[0009] Furthermore, the liquid epoxy resin is at least one of bisphenol A epoxy resin, bisphenol F epoxy resin, phenolic epoxy resin, reactive epoxy diluent, pre-reactant of polyurethane and epoxy resin, pre-reactant of dibasic acid and epoxy resin, pre-reactant of CTBN and epoxy resin, and grinding liquid of methyl methacrylate-butadiene-styrene and epoxy resin.

[0010] Furthermore, the solid epoxy resin is at least one of bisphenol A epoxy resin, bisphenol F epoxy resin, novolac epoxy resin, cresol novolac epoxy resin, bisphenol A formaldehyde epoxy resin, phenoxy resin, and oxazolidone epoxy resin.

[0011] Furthermore, the UV absorber is at least one of benzotriazoles, benzophenones, triazines, and composite UV absorbers.

[0012] Furthermore, the heat stabilizer is at least one of hindered amines, hindered phenols, phosphites, thioesters, and composite antioxidants.

[0013] Furthermore, the curing agent is at least one of dicyandiamide, 4,4'-diaminodiphenyl sulfone, 4,4'-diaminodiphenylmethane, amine adducts, hydrazides, and microcapsule curing agents.

[0014] Furthermore, the accelerator is at least one of tertiary amine, quaternary ammonium salt, imidazole, boron trifluoride amine, antimony pentafluoride amine, organic urea, and amine adduct.

[0015] Furthermore, the auxiliary agent may be at least one of a diluent, a stabilizer, a coupling agent, a defoaming agent, and a wetting and leveling agent.

[0016] Furthermore, a method for preparing a low-yellowing UV-resistant epoxy resin composition comprises selecting a curing agent and grinding it with a liquid epoxy resin into a slurry, heating and melting the solid epoxy resin and the liquid epoxy resin, cooling them to reach an equilibrium state, then adding the curing agent slurry and a UV absorber and a stabilizer additive, and stirring them evenly to form a finished product.

[0017] The present invention provides a low-yellowing UV-resistant epoxy resin composition and a preparation method thereof, which have the following beneficial effects: based on a relatively low-cost bisphenol A epoxy resin system, a certain degree of yellowing resistance and UV resistance can still be achieved by adding a UV absorber and a stabilizer; a certain low-yellowing curing effect can still be achieved by adding a stabilizer to a commonly used latent curing agent such as dicyandiamide and organic urea; and a certain amount of heat stabilizer can be added to inhibit the oxidative decomposition of the epoxy resin, thereby improving the weather resistance of the epoxy resin. DETAILED DESCRIPTION

[0018] The following examples are used to illustrate the present invention, but they are not intended to limit the scope of the present invention.

[0019] Example 1

[0020] The low-yellowing UV-resistant epoxy resin composition of this embodiment includes the following components:

[0021] 50 parts of solid epoxy resin E44 (i.e. bisphenol A type epoxy resin), 30 parts of liquid epoxy resin DEGDA EP (i.e. bisphenol A glycidyl ether diglycidyl stearate), 0.5 parts of UV absorber UV-P (i.e. 2-hydroxy-4-n-octyloxybenzophenone), 0.5 parts of heat stabilizer IRGAFFIN LX 600 (i.e. mixed antioxidant), 5 parts of dicyandiamide (BAD), 5 parts of accelerator DABCOTMCAT CX-20 (i.e. N,N',N"-trimethylhexahydrotriazine), and 0.1 parts of auxiliary agent BYK-392 (i.e. silicone defoamer).

[0022] Among them, the solid epoxy resin E44 is a commercially available epoxy resin, the liquid epoxy resin DEGDA EP is a commercially available epoxy resin, the UV absorber UV-P is a commercially available UV absorber, the heat stabilizer IRGAFFIN LX 600 is a commercially available heat stabilizer, the dicyandiamide (BAD) is a commercially available curing agent, the accelerator DABCOTM CAT CX-20 is a commercially available curing agent, and the additive BYK-392 is a commercially available additive.

[0023] The preparation method of the low-yellowing UV-resistant epoxy resin composition of this embodiment comprises the following steps:

[0024] Pour solid epoxy resin E44 and liquid epoxy resin DEGDA EP into a stirring tank, stir at 100°C until melted, then cool to 65°C, add UV absorber UV-P and heat stabilizer IRGAFFIN LX 600 and stir evenly to prepare component A;

[0025] Dicyandiamide (BAD), accelerator DABCOTM CAT CX-20, liquid epoxy resin, and additive BYK-392 are separately stirred and triaxially ground to form component B;

[0026] Add component B to component A, stir for 30 minutes and then divide into portions and freeze overnight.

[0027] Example 2

[0028] The low-yellowing UV-resistant epoxy resin composition of this embodiment includes the following components:

[0029] 55 parts of solid epoxy resin E51 (i.e. bisphenol F type epoxy resin), 25 parts of liquid epoxy resin DGDA EP (i.e. bisphenol A glycidyl ether diglycidyl laurate), 0.5 parts of UV absorber UV-P (i.e. 2-hydroxy-4-n-octyloxybenzophenone), 0.5 parts of heat stabilizer IRGAFFIN LX 600 (i.e. mixed antioxidant), 5 parts of dicyandiamide (BAD), 5 parts of accelerator DABCOTMCAT CX-20 (i.e. N,N',N"-trimethylhexahydrotriazine), and 0.1 parts of auxiliary agent BYK-392 (i.e. silicone defoamer).

[0030] Among them, the solid epoxy resin E51 is a commercially available epoxy resin, the liquid epoxy resin DGDA EP is a commercially available epoxy resin, the UV absorber UV-P is a commercially available UV absorber, the heat stabilizer IRGAFFIN LX 600 is a commercially available heat stabilizer, the dicyandiamide (BAD) is a commercially available curing agent, the accelerator DABCOTM CAT CX-20 is a commercially available curing agent, and the additive BYK-392 is a commercially available additive.

[0031] The preparation method of the low-yellowing UV-resistant epoxy resin composition of this embodiment comprises the following steps:

[0032] Pour solid epoxy resin E51 and liquid epoxy resin DGDA EP into a stirring tank, stir at 100°C until melted, then cool to 65°C, add UV absorber UV-P and heat stabilizer IRGAFFIN LX 600 and stir evenly to prepare component A;

[0033] Dicyandiamide (BAD), accelerator DABCOTM CAT CX-20, liquid epoxy resin, and additive BYK-392 are separately stirred and triaxially ground to form component B;

[0034] Add component B to component A, stir for 30 minutes and then divide into portions and freeze overnight.

[0035] Example 3

[0036] The low-yellowing UV-resistant epoxy resin composition of this embodiment includes the following components:

[0037] Solid epoxy resin E51 (i.e. bisphenol F type epoxy resin) 60 parts, liquid epoxy resin DGDA EP (i.e. bisphenol A glycidyl ether diglycidyl laurate) 20 parts, UV absorber UV-P (i.e. 2-hydroxy-4-n-octyloxybenzophenone) 1 part, heat stabilizer IRGAFFIN LX 600 (i.e. mixed antioxidant) 1 part, dicyandiamide (BAD) 5 parts, accelerator DABCOTM CATCX-20 (i.e. N,N',N"-trimethylhexahydrotriazine) 5 parts, auxiliary agent BYK-392 (i.e. silicone defoamer) 0.1 part.

[0038] Among them, the solid epoxy resin E51 is a commercially available epoxy resin, the liquid epoxy resin DGDA EP is a commercially available epoxy resin, the UV absorber UV-P is a commercially available UV absorber, the heat stabilizer IRGAFFIN LX 600 is a commercially available heat stabilizer, the dicyandiamide (BAD) is a commercially available curing agent, the accelerator DABCOTM CAT CX-20 is a commercially available curing agent, and the additive BYK-392 is a commercially available additive.

[0039] The preparation method of the low-yellowing UV-resistant epoxy resin composition of this embodiment comprises the following steps:

[0040] Pour solid epoxy resin E51 and liquid epoxy resin DGDA EP into a stirring tank, stir at 100°C until melted, then cool to 65°C, add UV absorber UV-P and heat stabilizer IRGAFFIN LX 600 and stir evenly to prepare component A;

[0041] Dicyandiamide (BAD), accelerator DABCOTM CAT CX-20, liquid epoxy resin, and additive BYK-392 are separately stirred and triaxially ground to form component B;

[0042] Add component B to component A, stir for 30 minutes and then divide into portions and freeze overnight.

[0043] Example 4

[0044] The low-yellowing UV-resistant epoxy resin composition of this embodiment includes the following components:

[0045] 55 parts of solid epoxy resin E51 (i.e. bisphenol F type epoxy resin), 25 parts of liquid epoxy resin DGDA EP (i.e. bisphenol A glycidyl ether diglycidyl laurate), 0.5 parts of UV absorber UV-P (i.e. 2-hydroxy-4-n-octyloxybenzophenone), 0.5 parts of heat stabilizer IRGAFFIN LX 600 (i.e. mixed antioxidant), 5 parts of dicyandiamide (BAD), 5 parts of accelerator DABCOTMCAT CX-20 (i.e. N,N',N"-trimethylhexahydrotriazine), and 0.1 parts of auxiliary agent BYK-392 (i.e. silicone defoamer).

[0046] Among them, the solid epoxy resin E51 is a commercially available epoxy resin, the liquid epoxy resin DGDA EP is a commercially available epoxy resin, the UV absorber UV-P is a commercially available UV absorber, the heat stabilizer IRGAFFIN LX 600 is a commercially available heat stabilizer, the dicyandiamide (BAD) is a commercially available curing agent, the accelerator DABCOTM CAT CX-20 is a commercially available curing agent, and the additive BYK-392 is a commercially available additive.

[0047] The preparation method of the low-yellowing UV-resistant epoxy resin composition of this embodiment comprises the following steps:

[0048] Pour solid epoxy resin E51 and liquid epoxy resin DGDA EP into a stirring tank, stir at 100°C until melted, then cool to 65°C, add UV absorber UV-P and heat stabilizer IRGAFFIN LX 600 and stir evenly to prepare component A;

[0049] Dicyandiamide (BAD), accelerator DABCOTM CAT CX-20, liquid epoxy resin, and additive BYK-392 are separately stirred and triaxially ground to form component B;

[0050] Add component B to component A, stir for 30 minutes and then divide into portions and freeze overnight.

[0051] Example 5

[0052] The low-yellowing UV-resistant epoxy resin composition of this embodiment includes the following components:

[0053] 55 parts of solid epoxy resin E51 (i.e. bisphenol F type epoxy resin), 25 parts of liquid epoxy resin DGDA EP (i.e. bisphenol A glycidyl ether diglycidyl laurate), 0.5 parts of UV absorber UV-P (i.e. 2-hydroxy-4-n-octyloxybenzophenone), 0.5 parts of heat stabilizer IRGAFFIN LX 600 (i.e. mixed antioxidant), 5 parts of dicyandiamide (BAD), 5 parts of accelerator DABCOTMCAT CX-20 (i.e. N,N',N"-trimethylhexahydrotriazine), and 0.1 parts of auxiliary agent BYK-392 (i.e. silicone defoamer).

[0054] Among them, the solid epoxy resin E51 is a commercially available epoxy resin, the liquid epoxy resin DGDA EP is a commercially available epoxy resin, the UV absorber UV-P is a commercially available UV absorber, the heat stabilizer IRGAFFIN LX 600 is a commercially available heat stabilizer, the dicyandiamide (BAD) is a commercially available curing agent, the accelerator DABCOTM CAT CX-20 is a commercially available curing agent, and the additive BYK-392 is a commercially available additive.

[0055] The preparation method of the low-yellowing UV-resistant epoxy resin composition of this embodiment comprises the following steps:

[0056] Pour solid epoxy resin E51 and liquid epoxy resin DGDA EP into a stirring tank, stir at 100°C until melted, then cool to 65°C, add UV absorber UV-P and heat stabilizer IRGAFFIN LX 600 and stir evenly to prepare component A;

[0057] Dicyandiamide (BAD), accelerator DABCOTM CAT CX-20, liquid epoxy resin, and additive BYK-392 are separately stirred and triaxially ground to form component B;

[0058] Add component B to component A, stir for 30 minutes and then divide into portions and freeze overnight.

[0059] Example 6

[0060] The low-yellowing UV-resistant epoxy resin composition of this embodiment includes the following components:

[0061] 55 parts of solid epoxy resin E51 (i.e. bisphenol F type epoxy resin), 25 parts of liquid epoxy resin DGDA EP (i.e. bisphenol A glycidyl ether diglycidyl laurate), 0.5 parts of UV absorber UV-P (i.e. 2-hydroxy-4-n-octyloxybenzophenone), 0.5 parts of heat stabilizer IRGAFFIN LX 600 (i.e. mixed antioxidant), 5 parts of dicyandiamide (BAD), 5 parts of accelerator DABCOTMCAT CX-20 (i.e. N,N',N"-trimethylhexahydrotriazine), and 0.1 parts of auxiliary agent BYK-392 (i.e. silicone defoamer).

[0062] Among them, the solid epoxy resin E51 is a commercially available epoxy resin, the liquid epoxy resin DGDA EP is a commercially available epoxy resin, the UV absorber UV-P is a commercially available UV absorber, the heat stabilizer IRGAFFIN LX 600 is a commercially available heat stabilizer, the dicyandiamide (BAD) is a commercially available curing agent, the accelerator DABCOTM CAT CX-20 is a commercially available curing agent, and the additive BYK-392 is a commercially available additive.

[0063] The preparation method of the low-yellowing UV-resistant epoxy resin composition of this embodiment comprises the following steps:

[0064] Pour solid epoxy resin E51 and liquid epoxy resin DGDA EP into a stirring tank, stir at 100°C until melted, then cool to 65°C, add UV absorber UV-P and heat stabilizer IRGAFFIN LX 600 and stir evenly to prepare component A;

[0065] Dicyandiamide (BAD), accelerator DABCOTM CAT CX-20, liquid epoxy resin, and additive BYK-392 are separately stirred and triaxially ground to form component B;

[0066] Add component B to component A, stir for 30 minutes and then divide into portions and freeze overnight.

[0067] Example 7

[0068] The low-yellowing UV-resistant epoxy resin composition of this embodiment includes the following components:

[0069] 55 parts of solid epoxy resin E51 (i.e. bisphenol F type epoxy resin), 25 parts of liquid epoxy resin DGDA EP (i.e. bisphenol A glycidyl ether diglycidyl laurate), 0.5 parts of UV absorber UV-P (i.e. 2-hydroxy-4-n-octyloxybenzophenone), 0.5 parts of heat stabilizer IRGAFFIN LX 600 (i.e. mixed antioxidant), 5 parts of dicyandiamide (BAD), 5 parts of accelerator DABCOTMCAT CX-20 (i.e. N,N',N"-trimethylhexahydrotriazine), and 0.1 parts of auxiliary agent BYK-392 (i.e. silicone defoamer).

[0070] Among them, the solid epoxy resin E51 is a commercially available epoxy resin, the liquid epoxy resin DGDA EP is a commercially available epoxy resin, the UV absorber UV-P is a commercially available UV absorber, the heat stabilizer IRGAFFIN LX 600 is a commercially available heat stabilizer, the dicyandiamide (BAD) is a commercially available curing agent, the accelerator DABCOTM CAT CX-20 is a commercially available curing agent, and the additive BYK-392 is a commercially available additive.

[0071] The preparation method of the low-yellowing UV-resistant epoxy resin composition of this embodiment comprises the following steps:

[0072] Pour solid epoxy resin E51 and liquid epoxy resin DGDA EP into a stirring tank, stir at 100°C until melted, then cool to 65°C, add UV absorber UV-P and heat stabilizer IRGAFFIN LX 600 and stir evenly to prepare component A;

[0073] Dicyandiamide (BAD), accelerator DABCOTM CAT CX-20, liquid epoxy resin, and additive BYK-392 are separately stirred and triaxially ground to form component B;

[0074] Add component B to component A, stir for 30 minutes and then divide into portions and freeze overnight.

[0075] Example 8

[0076] The low-yellowing UV-resistant epoxy resin composition of this embodiment includes the following components:

[0077] 55 parts of solid epoxy resin E51 (i.e. bisphenol F type epoxy resin), 25 parts of liquid epoxy resin DGDA EP (i.e. bisphenol A glycidyl ether diglycidyl laurate), 0.5 parts of UV absorber UV-P (i.e. 2-hydroxy-4-n-octyloxybenzophenone), 0.5 parts of heat stabilizer IRGAFFIN LX 600 (i.e. mixed antioxidant), 5 parts of dicyandiamide (BAD), 5 parts of accelerator DABCOTMCAT CX-20 (i.e. N,N',N"-trimethylhexahydrotriazine), and 0.1 parts of auxiliary agent BYK-392 (i.e. silicone defoamer).

[0078] Among them, the solid epoxy resin E51 is a commercially available epoxy resin, the liquid epoxy resin DGDA EP is a commercially available epoxy resin, the UV absorber UV-P is a commercially available UV absorber, the heat stabilizer IRGAFFIN LX 600 is a commercially available heat stabilizer, the dicyandiamide (BAD) is a commercially available curing agent, the accelerator DABCOTM CAT CX-20 is a commercially available curing agent, and the additive BYK-392 is a commercially available additive.

[0079] The preparation method of the low-yellowing UV-resistant epoxy resin composition of this embodiment comprises the following steps:

[0080] Pour solid epoxy resin E51 and liquid epoxy resin DGDA EP into a stirring tank, stir at 100°C until melted, then cool to 65°C, add UV absorber UV-P and heat stabilizer IRGAFFIN LX 600 and stir evenly to prepare component A;

[0081] Dicyandiamide (BAD), accelerator DABCOTM CAT CX-20, liquid epoxy resin, and additive BYK-392 are separately stirred and triaxially ground to form component B;

[0082] Add component B to component A, stir for 30 minutes and then divide into portions and freeze overnight.

[0083] Example 9

[0084] The low-yellowing UV-resistant epoxy resin composition of this embodiment includes the following components:

[0085] 55 parts of solid epoxy resin E51 (i.e. bisphenol F type epoxy resin), 25 parts of liquid epoxy resin DGDA EP (i.e. bisphenol A glycidyl ether diglycidyl laurate), 0.5 parts of UV absorber UV-P (i.e. 2-hydroxy-4-n-octyloxybenzophenone), 0.5 parts of heat stabilizer IRGAFFIN LX 600 (i.e. mixed antioxidant), 5 parts of dicyandiamide (BAD), 5 parts of accelerator DABCOTMCAT CX-20 (i.e. N,N',N"-trimethylhexahydrotriazine), and 0.1 parts of auxiliary agent BYK-392 (i.e. silicone defoamer).

[0086] Among them, the solid epoxy resin E51 is a commercially available epoxy resin, the liquid epoxy resin DGDA EP is a commercially available epoxy resin, the UV absorber UV-P is a commercially available UV absorber, the heat stabilizer IRGAFFIN LX 600 is a commercially available heat stabilizer, the dicyandiamide (BAD) is a commercially available curing agent, the accelerator DABCOTM CAT CX-20 is a commercially available curing agent, and the additive BYK-392 is a commercially available additive.

[0087] The preparation method of the low-yellowing UV-resistant epoxy resin composition of this embodiment comprises the following steps:

[0088] Pour solid epoxy resin E51 and liquid epoxy resin DGDA EP into a stirring tank, stir at 100°C until melted, then cool to 65°C, add UV absorber UV-P and heat stabilizer IRGAFFIN LX 600 and stir evenly to prepare component A;

[0089] Dicyandiamide (BAD), accelerator DABCOTM CAT CX-20, liquid epoxy resin, and additive BYK-392 are separately stirred and triaxially ground to form component B;

[0090] Add component B to component A, stir for 30 minutes and then divide into portions and freeze overnight.

[0091] Example 10

[0092] The low-yellowing UV-resistant epoxy resin composition of this embodiment includes the following components:

[0093] 55 parts of solid epoxy resin E51 (i.e. bisphenol F type epoxy resin), 25 parts of liquid epoxy resin DGDA EP (i.e. bisphenol A glycidyl ether diglycidyl laurate), 0.5 parts of UV absorber UV-P (i.e. 2-hydroxy-4-n-octyloxybenzophenone), 0.5 parts of heat stabilizer IRGAFFIN LX 600 (i.e. mixed antioxidant), 5 parts of dicyandiamide (BAD), 5 parts of accelerator DABCOTMCAT CX-20 (i.e. N,N',N"-trimethylhexahydrotriazine), and 0.1 parts of auxiliary agent BYK-392 (i.e. silicone defoamer).

[0094] Among them, the solid epoxy resin E51 is a commercially available epoxy resin, the liquid epoxy resin DGDA EP is a commercially available epoxy resin, the UV absorber UV-P is a commercially available UV absorber, the heat stabilizer IRGAFFIN LX 600 is a commercially available heat stabilizer, the dicyandiamide (BAD) is a commercially available curing agent, the accelerator DABCOTM CAT CX-20 is a commercially available curing agent, and the additive BYK-392 is a commercially available additive.

[0095] The preparation method of the low-yellowing UV-resistant epoxy resin composition of this embodiment comprises the following steps:

[0096] Pour solid epoxy resin E51 and liquid epoxy resin DGDA EP into a stirring tank, stir at 100°C until melted, then cool to 65°C, add UV absorber UV-P and heat stabilizer IRGAFFIN LX 600 and stir evenly to prepare component A;

[0097] Dicyandiamide (BAD), accelerator DABCOTM CAT CX-20, liquid epoxy resin, and additive BYK-392 are separately stirred and triaxially ground to form component B;

[0098] Add component B to component A, stir for 30 minutes and then divide into portions and freeze overnight.

[0099] Comparative Example 1

[0100] The low-yellowing UV-resistant epoxy resin composition of this comparative example comprises the following components:

[0101] 55 parts of solid epoxy resin E51 (i.e. bisphenol F type epoxy resin), 25 parts of liquid epoxy resin DGDA EP (i.e. bisphenol A glycidyl ether diglycidyl laurate), 5 parts of dicyandiamide (BAD), 5 parts of accelerator DABCOTM CAT CX-20 (i.e. N,N',N"-trimethylhexahydrotriazine), and 0.1 parts of auxiliary agent BYK-392 (i.e. silicone defoamer).

[0102] Among them, the solid epoxy resin E51 is a commercially available epoxy resin, the liquid epoxy resin DGDA EP is a commercially available epoxy resin, the dicyandiamide (BAD) is a commercially available curing agent, the accelerator DABCOTM CAT CX-20 is a commercially available curing agent, and the auxiliary agent BYK-392 is a commercially available auxiliary agent.

[0103] The preparation method of the low-yellowing UV-resistant epoxy resin composition of this comparative example comprises the following steps:

[0104] Pour solid epoxy resin E51 and liquid epoxy resin DGDA EP into a stirring tank, stir at 100°C until melted, then cool to 65°C, add dicyandiamide (BAD), accelerator DABCOTM CAT CX-20, liquid epoxy resin, and additive BYK-392, stir evenly to prepare component A;

[0105] Add component B to component A, stir for 30 minutes and then divide into portions and freeze overnight.

[0106] Test example

[0107] The yellowing value, yellowing resistance, weather resistance, adhesion, and medium resistance of the samples obtained in Examples 1 to 10 and Comparative Example 1 were tested, and the results are listed in Table 1.

[0108]

[0109] In Examples 1-10, due to the addition of UV absorbers and heat stabilizers, the yellowing value is relatively low, between 2.8-3.2, while in Comparative Example 1, due to the absence of these anti-yellowing components, the yellowing value is as high as 6.5. This shows that UV absorbers and heat stabilizers can effectively inhibit the yellowing phenomenon of the epoxy resin composition under the influence of light or other environmental factors, and significantly improve its yellowing resistance. All examples and comparative examples show stable medium resistance, indicating that when in contact with common chemical media (such as acids, alkalis, solvents, etc.), the epoxy resin composition has a certain resistance and can maintain the integrity of the structure and performance in a variety of chemical environments without significant degradation or damage. This feature makes the composition reliable in application scenarios where it may be exposed to chemical substances. The examples show good weather resistance, which means that they can maintain relatively stable physical and chemical properties under different climatic conditions (such as ultraviolet irradiation, temperature changes, humidity changes, etc.), reducing performance degradation caused by environmental factors. The weather resistance of Comparative Example 1 is average, indicating that the lack of UV absorber and heat stabilizer will reduce the durability of the epoxy resin composition in a complex environment. It can be seen from Table 1 that the yellowing values ​​of the low-yellowing UV-resistant epoxy resin compositions obtained in Examples 1 to 10 are all less than that of Comparative Example 1, while other physical and chemical indicators are basically the same, indicating that the low-yellowing UV-resistant epoxy resin compositions obtained in Examples 1 to 10 have good low-yellowing performance.

[0110] The embodiments of the present invention are given for the purpose of illustration and description, and are not intended to be exhaustive or to limit the invention to the disclosed forms. Many modifications and variations will be apparent to those of ordinary skill in the art. The embodiments are selected and described in order to better illustrate the principles and practical applications of the present invention and to enable those of ordinary skill in the art to understand the present invention and thereby design various embodiments with various modifications suitable for specific uses.

Claims

1. A low-yellowing UV-resistant epoxy resin composition, characterized in that: The proportions are as follows: 50-60 parts of solid epoxy resin, 10-40 parts of liquid epoxy resin, 0.1-5 parts of UV absorber, 0.1-5 parts of heat stabilizer, 3-10 parts of dicyandiamide, 3-10 parts of accelerator, and 0.01-1 parts of auxiliary agent; The preparation method is as follows: pour solid epoxy resin and liquid epoxy resin into a stirring tank, stir at 100°C until melted, then cool to 65°C, add UV absorber and heat stabilizer and stir evenly to prepare component A; Dicyandiamide, accelerator, liquid epoxy resin, and auxiliary agent are separately stirred and three-axis ground to form component B; Add component B to component A, stir for 30 minutes and then divide into portions and freeze overnight.

2. A low-yellowing UV-resistant epoxy resin composition according to claim 1, characterized in that: The liquid epoxy resin is at least one of bisphenol A epoxy resin, bisphenol F epoxy resin, novolac epoxy resin, reactive epoxy diluent, pre-reactant of polyurethane and epoxy resin, pre-reactant of dibasic acid and epoxy resin, pre-reactant of CTBN and epoxy resin, and grinding liquid of methyl methacrylate-butadiene-styrene and epoxy resin.

3. A low-yellowing UV-resistant epoxy resin composition according to claim 2, characterized in that: The solid epoxy resin is at least one of bisphenol A epoxy resin, bisphenol F epoxy resin, novolac epoxy resin, cresol novolac epoxy resin, bisphenol A formaldehyde epoxy resin, phenoxy resin, and oxazolidone epoxy resin.

4. A low-yellowing UV-resistant epoxy resin composition according to claim 3, characterized in that: The UV absorber is at least one of benzotriazole, benzophenone, triazine and compound UV absorbers.

5. A low-yellowing UV-resistant epoxy resin composition according to claim 4, characterized in that: The heat stabilizer is at least one of hindered amines, hindered phenols, phosphites, thioesters, and composite antioxidants.

6. A low-yellowing UV-resistant epoxy resin composition according to claim 5, characterized in that: The curing agent is at least one of dicyandiamide, 4,4'-diaminodiphenyl sulfone, 4,4'-diaminodiphenylmethane, amine adduct, hydrazide and microcapsule curing agent.

7. A low-yellowing UV-resistant epoxy resin composition according to claim 6, characterized in that: The accelerator is at least one of tertiary amine, quaternary ammonium salt, imidazole, boron trifluoride amine, antimony pentafluoride amine, organic urea and amine adduct.

8. A low-yellowing UV-resistant epoxy resin composition according to claim 7, characterized in that: The auxiliary agent may be at least one of a diluent, a stabilizer, a coupling agent, a defoaming agent, and a wetting and leveling agent.

9. A method for preparing a low-yellowing UV-resistant epoxy resin composition according to any one of claims 1 to 8, characterized in that: Select a curing agent and grind it with liquid epoxy resin into a slurry. Heat and melt the solid epoxy resin and liquid epoxy resin, then cool them down to reach a balanced state. Then add the curing agent slurry, UV absorber, and stabilizer additives, and stir evenly to make the finished product.

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