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Method for lowering curing temperature and preventing skinning of bismaleimide resin and modified resin

A technology of modified resin and double horse resin, applied in the field of thermosetting resin, can solve the problems of large amount of addition, easy formation of skin injection, quick skin formation on free surface, etc.

Active Publication Date: 2014-02-05
AVIC COMPOSITES
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

By adding some other substances, such as epoxy resin, benzoxazine and other substances, the curing temperature can be reduced, such as the document "Properties of Toughened Bismaleimide and Allyl Benzoxazine Blends" ( Gu Yi et al., Aerospace Materials Technology 2012, Issue 5, pages 45-50) and "Benzoxazine–bismaleimide blends: Curing and thermal properties" (Santhosh Kumar KS et al., European Polymer Journal 2007, 43:5084–5096) etc. reported Use benzoxazine to modify the thermal curing properties of bis-horse resin, but the exothermic peak will obviously move to the low-temperature section when the addition amount is very high, such as reaching more than 30%, which will inevitably lead to a decrease in the heat resistance of the final resin , and the curing peak span is very large, and the termination point is still the same as that of the double horse resin used, so in fact, a high temperature is still required to achieve full curing
"Synthesis and Properties of Solvent-free Medium-temperature Curing Bismaleimide Resin" (Ren Hongyan et al., Plastic Industry 2010, Issue 6, Pages 1-3, 7) reported the use of epoxy resin modification to reduce the curing of bismaleimide resin Temperature research, but the addition amount is large (mass ratio 1:1) and there is still a curing peak of Shuangma resin in the high temperature section, indicating that high temperature treatment is actually required to completely cure the resin
[0004] For most allylphenol-modified bis-horse resins, there is also a problem that the free surface will quickly skin during the curing process, and due to the uneven internal curing shrinkage, the surface will subsequently wrinkle and form large undulations , resulting in serious potholes on the surface of the final cast body
However, the reason for the skinning of Shuangma resin is still unclear and there are few reports. It may be caused by surface oxidative polymerization and internal thermal fluctuation and shrinkage, which makes it difficult for Shuangma resin to be directly used as a vacuum for coatings and composite materials. Bag molding and other processes, and it is also easy to form skins during the injection process, making injection difficult
However, most of the current research on Shuangma resin focuses on the synthesis of new resins, formulations and toughening and composite materials of Shuangma resin. There are very few reports on this aspect, and a document that can be retrieved (J.Mater.Sci. 42:9170-9175) involves the doping of a quaternary ammonium salt of an amphiphilic copolymer to reduce the volume shrinkage of bima resin curing, thereby reducing surface shrinkage, but this high polymer needs to be dissolved in a solvent in advance and then Doped into Shuangma resin, the solvent needs to be removed before curing, which increases the steps and difficulty of the molding process

Method used

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  • Method for lowering curing temperature and preventing skinning of bismaleimide resin and modified resin
  • Method for lowering curing temperature and preventing skinning of bismaleimide resin and modified resin
  • Method for lowering curing temperature and preventing skinning of bismaleimide resin and modified resin

Examples

Experimental program
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Effect test

Embodiment 1

[0035] Add methyl ethyl ketone oxime or benzophenone oxime or cyclohexanone oxime to a kind of Shuangma resin 6421 (product of Beijing Institute of Aeronautical Materials) or Shuangma resin XU292 or Shuangma resin QY8911, and the amount added is 100% of the quality of Shuangma resin 1% or 2% or 3%, stir and mix evenly at 110°C or 98°C to obtain a modified resin that reduces the curing temperature and improves surface shrinkage after curing.

[0036] After the modified resin prepared in this example is cured according to the conventional procedure, the height of the surface shrinkage of the cured modified resin is reduced from ~1.3 mm to less than 0.1 mm, and the surface is smooth and shiny.

[0037] During the curing process, the comparison between the pure double horse 6421 that is not doped with ketoxime and the resin compound doped with the ketoxime described in this example is as follows:

[0038] Table 1. Curing process monitoring of pure Bima resin and modified Bima resi...

Embodiment 2

[0050] Self-prepared a kind of allylphenol modified double horse resin, every 100g double horse resin contains 60g of 4,4'-diaminodiphenylmethane bismaleimide, 35g of allyl bisphenol A, polyethersulfone 5g (toughener) or 4,4'-diaminodiphenyl ether bismaleimide per 100g bisma resin, 25g allyl bisphenol A, 20g allyl phenol, phenolphthalein modified polyether Sulfone 7g (toughening agent) or 4,4'-diaminodiphenyl ether bismaleimide and m-phenylenediamine bismaleimide in a mass ratio of 2:1 per 100g bisma resin Mix 55g of bismaleimide, 30g of allyl bisphenol A, and 15g of carbon black (conductive and thermal conductivity modifier). Then add butyraldehyde oxime or cyclohexanone oxime or benzophenone oxime, the addition amount is 0.8g or 2.1g or 4g, stir and mix evenly at 105°C, and obtain the double horse resin relative to the additive without ketoxime or aldoxime Modified resin that reduces curing temperature and improves surface shrinkage after curing.

Embodiment 3

[0052] Self-prepared a kind of allylphenol modified double horse resin, every 100g double horse resin contains 42g of 4,4'-diaminodiphenyl sulfone bismaleimide, 35g of diallyl bisphenol A, phenolphthalein modified 23g of permanent polyaryletherketone (toughening agent) or 48g of 4,4'-diaminodiphenyl ether bismaleimide per 100g of double horse resin, 25g of diallyl bisphenol F, allyl phenol 20g (reactive diluent), 7g of nano-silica (toughener) or 4,4'-diaminobenzophenone bismaleimide and 4,4'-diamino in every 100g bisma resin 55 g of mixed bismaleimide with a mass ratio of diphenylmethane bismaleimide of 1:1, 30 g of diallyl bisphenol A, and 15 g of silver nanoparticles (conductivity modifier). Then add cyclohexanone oxime or a mixture of p-methoxybenzophenone oxime and benzophenone oxime with a mass ratio of 1:1, the addition amount is 1.6g or 4.2g, and stir and mix evenly at 90°C to obtain Modified resins with added ketoxime or aldoxime additives to reduce curing temperature...

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Abstract

The invention relates to a method for preventing skinning on the surface of bismaleimide resin in curing and lowering the curing temperature of the bismaleimide resin. By adding little ketoxime or ketoxime substance into the bismaleimide resin, the skinning phenomenon when the bismaleimide resin is cured and the problems such as unfairness of the cured article surface and resin injection can be effectively prevented; moreover, after adding little ketoxime or ketoxime substance, the curing heat release peak-to-peak value temperature of the bismaleimide resin is greatly reduced by more than 30DEG C, and the heat release peak is narrowed; after the bismaleimide resin is cured under the same condition, the vitrification conversion temperature (DMA method) can be greatly increased by 40DEG C, and the application advantages of the bismaleimide resin on the aspects of curing resin, paint, cured resin and the like at a low temperature and utilizing the resin, paint, cured resin and the like at a high temperature can be improved through the modified resin.

Description

technical field [0001] The invention relates to a method for reducing the curing temperature of double-horse resin and anti-skinning and a modified resin, belonging to the technical field of thermosetting resins. Background technique [0002] Thermosetting resins have a very wide range of applications, such as cast resins, coatings, composite materials and other fields. Compared with thermoplastic resins, thermosetting resins have higher hardness, strength, heat resistance, and have excellent solvent resistance and processability. As a large category of thermosetting resins, Shuangma resin has also received extensive attention. Its cured resin has excellent heat resistance (the glass transition temperature can reach more than 300°C) and mechanical properties, and its cost and molding process difficulty are much lower than that of polyimide resin, which is also a high-temperature resistant resin. The fields with high heat resistance of materials, especially the aerospace fi...

Claims

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Application Information

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IPC IPC(8): C08L79/08C08K5/33
CPCC08G61/124C08G61/125C08G2261/12C08G2261/3221C08G2261/46C08G2261/592C08G2261/60C08K5/33C08L65/00C08L81/06C08L71/00C08L15/00
Inventor 郭妙才
Owner AVIC COMPOSITES