A dihydric alcohol-modified anhydride flexibilizer

Abstract

The application relates to a dihydric alcohol modified anhydride toughening agent, characterized by being prepared by the following method: dihydric alcohol is vacuum dehydrated at 100 DEG C, and nitrogen is passed after dehydration; equimolar anhydride functional group anhydride is added and reacted at a temperature range of 100 DEG C-150 DEG C, and the dihydric alcohol modified anhydride toughening agent is obtained after the reaction is completed. The dihydric alcohol modified anhydride toughening agent can improve the elongation at break, makes the resin after curing more flexible, and also meets the requirements of tensile strength. The dihydric alcohol modified anhydride toughening agent has little influence on the glass transition temperature of a high-temperature curing system, and has a wide application prospect.

Description

Technical Field

[0001] This invention relates to the field of toughening agent preparation, specifically to a diol-modified acid anhydride toughening agent. Background Technology

[0002] In epoxy curing systems, bisphenol A or bisphenol F epoxy resins are typically reacted with amine or anhydride curing agents, and these systems are widely used. However, the brittleness of epoxy resins directly affects their further use, and in many applications, excessive brittleness and easy cracking are common problems. Most formulations require toughening modification to improve the impact resistance and elongation at break of the finished product.

[0003] Toughening usually sacrifices the strength and glass transition temperature of the cured product. Therefore, a toughening agent that has little impact on the bulk strength and glass transition temperature is essential.

[0004] Currently, most toughening agents are epoxy resin modified products or rubber modified products, which need to be added to the main agent when applied, thus limiting the flexibility of the overall formulation. Summary of the Invention

[0005] In order to overcome the above-mentioned defects of the prior art, the present invention aims to provide a diol-modified anhydride toughening agent. When the toughening agent of the present invention is added to the curing agent system, it greatly improves the flexibility of the system and has excellent toughening effect, with little impact on the bulk strength and glass transition temperature.

[0006] A diol-modified acid anhydride toughening agent is prepared by the following method:

[0007] The diol was dehydrated under vacuum at 100°C, and nitrogen gas was introduced after the dehydration was complete.

[0008] An anhydride with equimolar functional groups is added and reacted within a temperature range of 100℃-150℃. After the reaction is complete, the diol-modified anhydride toughening agent is obtained.

[0009] In a preferred embodiment of the present invention, the diol includes any one or more of ethylene glycol, 1,2-butanediol, 1,4-butanediol, 1,6-hexanediol, 2-methyl-2,4-pentanediol, or 1,2-propanediol.

[0010] Preferably, it is any one or more of 1,4-butanediol, 1,6-hexanediol or 2-methyl-2,4-pentanediol.

[0011] In a preferred embodiment of the present invention, the acid anhydride includes any one or more of methyltetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, methylnadic anhydride, maleic anhydride, or phthalic anhydride.

[0012] Preferably, it is one or more of methyltetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, or methylnadic anhydride.

[0013] In a preferred embodiment of the present invention, the diol-modified anhydride toughening agent is prepared by the reaction method of Formula 1 as follows:

[0014]

[0015] In a preferred embodiment of the present invention, the diol-modified anhydride toughening agent is prepared by the reaction method of Formula 2 as follows:

[0016]

[0017] In a preferred embodiment of the present invention, the diol-modified anhydride toughening agent is prepared by the reaction method of Formula 3 as follows:

[0018]

[0019] In a preferred embodiment of the present invention, the diol-modified anhydride toughening agent is prepared by the reaction method of Formula 4 as follows:

[0020]

[0021] The beneficial effects of this invention are:

[0022] The diol-modified anhydride toughening agent of this invention can improve the elongation at break, making the cured resin more tough, and the tensile strength also meets the requirements. It has minimal impact on the glass transition temperature of high-temperature curing systems and has broad application prospects. Detailed Implementation

[0023] The design principle of this invention is as follows:

[0024] The product of this invention is a modified acid anhydride. When applied, it is added to the curing agent system, which greatly improves the system's flexibility and has an excellent toughening effect, while having little impact on the bulk strength and glass transition temperature.

[0025] During the research process, this invention discovered that the selection and control of temperature has a significant impact on the performance of the product; the higher the temperature, the more vigorous the polymerization reaction.

[0026] Therefore, adjustments need to be made within the standard range to ensure the toughening effect meets the requirements. The same raw materials will yield different products at different reaction temperatures; therefore, the reaction temperature should be carefully determined and strictly controlled during the synthesis process.

[0027] When the reaction temperature is below 100℃, the ring-opening of the acid anhydride is not easy, the reaction is weak, and a brownish-yellow liquid is obtained. The toughening effect is not obvious when added to the curing agent system (as in Comparative Example 1). When the reaction temperature is above 150℃, the synthesis reaction is vigorous, the product has a higher degree of cross-linking, and it can play a toughening role, but it causes a loss of bulk strength and a greater loss of glass transition temperature (as in Comparative Example 2).

[0028] The present invention will be explained below with reference to specific embodiments:

[0029] Example 1

[0030] A. Take 80g of BDO into a flask, turn on the stirrer, heat to 100℃, turn on the vacuum, the temperature will rise to about 110℃, control the temperature at 110±5℃, vacuum dehydrate for 1 hour;

[0031] B. Turn off the vacuum, add 295g of MTHPA. The temperature will drop significantly. Purge with nitrogen and raise the temperature to 110°C. Control the temperature at 110-120°C and react for 1 hour.

[0032] C. Once the reaction is complete, discharge the material while it is still hot to obtain a brownish-yellow liquid, which is solid at room temperature.

[0033] In a curing system consisting of epoxy resin (A1) with 128 as the main component and curing agent (B1) with MTHPA as the main component, 2% (by mass) of BDO-modified MTHPA was added to B1 to obtain B2. Data comparisons were obtained from casting samples as follows: Table 1 Mechanical data of the 128 / MTHPA system with added BDO-modified MTHPA.

[0034] Table 1 Mechanical data of BDO-modified MTHPA in the 128 / MTHPA system

[0035]

[0036]

[0037] Note: A1:B1 = A1:B2, the curing conditions are 100℃, 3h.

[0038] Example 2

[0039] A. Take 100g of 1,6-HDO into a flask, turn on the stirr, heat to 100℃, turn on the vacuum, the temperature will rise to about 110℃, control the temperature at 110±5℃, vacuum dehydrate for 1h;

[0040] B. Turn off the vacuum, add 281g of MTHPA. The temperature will drop significantly. Purge with nitrogen and raise the temperature to 110°C. Control the temperature at 110-120°C and react for 1 hour.

[0041] C. Once the reaction is complete, discharge the material while it is still hot to obtain a brownish-yellow liquid, which is solid at room temperature.

[0042] In a curing system consisting of epoxy resin (A1) with 128 as the main component and curing agent (B1) with MTHPA as the main component, 4% (by mass) of 1,6-HDO-modified MTHPA was added to B1 to obtain B3. Data comparisons were obtained from casting samples as follows: Table 2 shows the mechanical data of the 128 / MTHPA system with added HDO-modified MTHPA.

[0043] Table 2 Mechanical data of 128 / MTHPA system modified with 1,6-HDO

[0044]

[0045] Note: A1:B1 = A1:B3, the curing conditions are 100℃, 3h.

[0046] Example 3

[0047] A. Take 80g of BDO into a flask, turn on the stirrer, heat to 100℃, turn on the vacuum, the temperature will rise to about 110℃, control the temperature at 110±5℃, vacuum dehydrate for 1 hour;

[0048] B. Turn off the vacuum, add 316g of NMA, the temperature will drop significantly, introduce nitrogen gas, raise the temperature to 130℃, control the temperature at 130-140℃, and react for 1 hour.

[0049] C. Once the reaction is complete, discharge the material while it is still hot to obtain a brownish-yellow liquid, which is solid at room temperature.

[0050] In a curing system consisting of epoxy resin (A2) with AG-80 as the main component and curing agent (B4) with NMA as the main component, 2% (by mass) of BDO-modified MTHPA was added to B4 to obtain B5. Data comparisons were obtained from casting samples as follows:

[0051] Table 3 Mechanical data of BDO-modified NMA in AG-80 / NMA system

[0052]

[0053] Note: A2:B4 = A2:B5, the curing conditions are 100℃ 1h + 150℃ 1h + 200℃ 1h.

[0054] Example 4

[0055] By weight percentage, the raw materials for component A of the epoxy resin composition are: 88% bisphenol A epoxy resin (brand E54) with an epoxy equivalent of 175-190 g / equivalent, 11% 1,4-butanediol diglycidyl ether, and C... 12-C 14 It contains 0.8% glycidyl ether, 0.15% propyltrimethoxysilane, and 0.05% antioxidant 1010.

[0056] By weight percentage, the raw materials of component B of the epoxy resin mixture are: 67% polyetheramine (D230), 30% N-aminoethylpiperazine, and 3% 2-phenylimidazole.

[0057] The weight ratio of component A to component B is 100:30.

[0058] The fiber-reinforced fabric has a modulus of 120,000 N / mm². 2 The glass fiber accounts for 71% of the weight of the epoxy resin composition.

[0059] The viscosity of the epoxy resin mixture was determined to be 212 mps using the DIN53015 method.

[0060] Example 5

[0061] A. Take 100g of 1,6-HDO into a flask, turn on the stirr, heat to 100℃, turn on the vacuum, the temperature will rise to about 110℃, control the temperature at 110±5℃, vacuum dehydrate for 1h;

[0062] B. Turn off the vacuum, add 302g of NMA, the temperature will drop significantly, introduce nitrogen gas, raise the temperature to 130℃, control the temperature at 130-140℃, and react for 1 hour.

[0063] C. After the reaction is complete, discharge the material while it is still hot to obtain a brownish-yellow liquid, which is solid at room temperature. The fiber-reinforced fabric has a modulus of 120,000 N / mm². 2 The carbon fiber accounts for 71% of the weight of the epoxy resin composition.

[0064] In a curing system consisting of epoxy resin (A2) with AG-80 as the main component and curing agent (B4) with NMA as the main component, 4% (by mass) of 1,6-HDO-modified MTHPA was added to B4 to obtain B6. Data comparisons were obtained from casting samples as follows:

[0065] Table 4 Mechanical data of AG-80 / NMA system with 1,6-HDO modification

[0066]

[0067] Note: A2:B4 = A2:B6, the curing conditions are 100℃ 1h + 150℃ 1h + 200℃ 1h.

[0068] Comparative Example 1

[0069] A. Take 100g of 1,6-HDO into a flask, turn on the stirr, heat to 100℃, turn on the vacuum, the temperature will rise to about 110℃, control the temperature at 110±5℃, vacuum dehydrate for 1h;

[0070] B. After the vacuum is turned off and the temperature drops to 100℃, add 302g of NMA. The temperature will drop significantly. Then, introduce nitrogen gas and raise the temperature to 90℃. Control the temperature at 85-95℃ and react for 1 hour.

[0071] C. Once the reaction is complete, discharge the material while it is still hot to obtain a brownish-yellow liquid, which is solid at room temperature. The fiber-reinforced fabric is carbon fiber with a modulus of 120,000 N / mm², accounting for 71% of the weight of the epoxy resin composition.

[0072] In a curing system consisting of epoxy resin (A2) with AG-80 as the main component and curing agent (B4) with NMA as the main component, 4% (by mass) of 1,6-HDO low-temperature modified MTHPA was added to B4 to obtain B7. Data comparisons were obtained from casting samples as follows:

[0073] Table 5 Mechanical data of HDO-modified NMA in AG-80 / NMA system at low temperature

[0074]

[0075]

[0076] Note: A2:B4 = A2:B7, the curing conditions are 100℃ 1h + 150℃ 1h + 200℃ 1h.

[0077] Comparative Example 2

[0078] A. Take 100g of 1,6-HDO into a flask, turn on the stirr, heat to 100℃, turn on the vacuum, the temperature will rise to about 110℃, control the temperature at 110±5℃, vacuum dehydrate for 1h;

[0079] B. Turn off the vacuum, add 302g of NMA, the temperature will drop significantly, introduce nitrogen gas, raise the temperature to 160℃, control the temperature at 160-170℃, and react for 1 hour.

[0080] C. Once the reaction is complete, discharge the material while it is still hot to obtain a brownish-yellow liquid, which is solid at room temperature. The fiber-reinforced fabric is carbon fiber with a modulus of 120,000 N / mm², accounting for 71% of the weight of the epoxy resin composition.

[0081] In a curing system consisting of epoxy resin (A2) with AG-80 as the main component and curing agent (B4) with NMA as the main component, 4% (by mass) of 1,6-HDO low-temperature modified MTHPA was added to B4 to obtain B8. Data comparisons were obtained from casting samples as follows:

[0082] Table 6 Mechanical data of HDO-modified NMA in AG-80 / NMA system at high temperature

[0083]

[0084] Note: A2:B4 = A2:B8, the curing conditions are 100℃ 1h + 150℃ 1h + 200℃ 1h.

Claims

1. A diol-modified anhydride toughening agent, characterized in that, It is prepared by the following method: The diol was dehydrated under vacuum at 100°C, and nitrogen gas was introduced after the dehydration was complete. Anhydrides with added equimolar functional groups; The diol-modified anhydride toughening agent is prepared by the reaction method of Formula 1 as follows: Formula 1; Alternatively, the diol-modified anhydride toughening agent may be prepared by the reaction method of Formula 2 as follows: Formula 2; Alternatively, the diol-modified anhydride toughening agent may be prepared by the reaction method of Formula 3 as follows: Formula 3; Alternatively, the diol-modified anhydride toughening agent may be prepared by the reaction method of Formula 4 below: Formula 4.

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