CN1111186C - Single-component thermosetting epoxy resin system - Google Patents

Abstract

The present invention relates to a class of one-component heat-curing epoxy resin systems that can be stored for a long time at room temperature. The present invention adds an onium salt to the epoxy resin as the main catalyst and an active hydrogen donor as a co-catalyst, wherein the onium salt is mainly iodonium salt or sulfonium salt, and the general structural formula of the iodonium salt is R ₃ -I ⁺ -R ₄ ·A ^- , the general structural formula of the sulfonium salt is formula I; the general structural formula of the synergistic catalyst is formula II, the main catalyst is 1 to 10% (wt) of the total weight, the ratio of the main catalyst to the synergistic catalyst The range is 1:2 to 2:1. The invention can be stored at room temperature for more than one year, and is a single component, and is suitable for technologies such as composite material liquid forming prepreg lamination molding, electronic potting material and the like.

Description

One-component heat-curing epoxy resin system

The present invention relates to a class of one-component heat-curing epoxy resin systems that can be stored for a long time at room temperature.

Epoxy resin systems usually consist of epoxy resin and curing agent. Curing agents include amines, acid anhydrides and latent curing agents, etc. Although the conventional epoxy resin system has good bonding performance and chemical resistance, the applicable process cycle of the resin system is relatively short. The storage period is only a few hours, so the requirements of its transportation and process operation cannot be satisfied well, and the requirements of its process operation can only be satisfied after some refrigeration measures are taken to them. If an appropriate amount of accelerator is added to the resin, although the curing cycle is shortened and the curing temperature is lowered, the storage properties at room temperature are further deteriorated. If it is stored in two-component form, it is more inconvenient to use, not to mention that some products cannot be stored in two-component form (such as epoxy resin used to prepare composite material prepregs). Therefore, at home and abroad, a lot of research work has been done on improving the storage performance of the resin and improving the reactivity of the resin. Japanese patent JP57-192428 has provided a composite system of trialkanoic acid amine boron and catechol to catalyze the amine curing ring. Oxygen; U.S.P4101459 uses difluoromethanesulfonate to catalyze amine curing epoxy; U.S.P4447586 uses copper fluoroborate as a catalyst; and U.S.P5134239 uses a class of compounds called π electron acceptors as catalysts. These patents provide Although technology can improve the room temperature storage performance of the resin system, its room temperature storage period is only 20 to 30 days.

The purpose of the present invention is to solve the room temperature storage performance of the thermosetting resin system to meet the requirements of composite materials, adhesives and electronic potting and packaging materials for epoxy resin one-component technology.

Technical solution of the present invention is, in epoxy resin, add the main catalyst onium salt (iodonium salt or sulfonium salt) of 1～10% (wt) of resin system gross weight, 0.5～5% synergistic catalyst active hydrogen The donor; where the epoxy resin can be of the following types:

(1) glycidyl ether epoxy;

(2) glycidyl ester epoxy;

(3) Alicyclic epoxy;

(4) Aliphatic epoxy.

The onium salt of the main catalyst is mainly iodonium salt or sulfonium salt; the general structural formula of iodonium salt is: R ₃ -I ⁺ -R ₄ ·A

负离子A^-为以下结构之一：S_bF₆ ^-，A₃F₆ ^-，PF₆ ^-，BF₄ ^-协同催化剂——活性氢供给体的结构通式为：

R ₃ is one of the following groups: R ₄ is one of the following groups: The general structural formula of sulfonium salt is: R' ₁ , R' ₂ , and R' ₃ are each one of the following groups:

Negative ion A ^- is one of the following structures: S _b F ₆ ^- , A ₃ F ₆ ^- , PF ₆ ^- , BF ₄ ^- Synergistic catalyst—the general structure formula of active hydrogen donor is:

R ₁ is one of the following groups: -CH ₃ , -CH ₂ CH ₃ , -CH ₂ CH ₂ CH ₃ etc.

R ₂ is one of the following groups: -CH ₃ , OCH ₃ , OCH ₂ CH ₃ etc.

The ratio of the main catalyst to the co-catalyst ranges from 1:2 to 2:1.

The advantage of the present invention is that since the main catalyst used in the epoxy resin is an onium salt, and the co-catalyst is an active hydrogen donor, the storage period of the resin at room temperature can reach more than one year, and because it is a single component, its transportation and The process operation is convenient and simple, which saves the production cost and simplifies the production process, and this kind of resin can be made into a single-component low-viscosity resin for long-term storage, so it is convenient to be used in the liquid forming technology of composite materials.

Example:

1. Select 97 parts of E54 epoxy, 2 parts of diphenyliodonium hexafluoroantimonate and 1.5 parts of acetylacetone, mix together, heat to 50-70°C and stir for 5 minutes to obtain a homogeneous resin system.

2. Select 97 parts of TDE85 epoxy resin, 2 parts of diphenyliodonium hexafluoroantimonate and 1.5 parts of acetylacetone, mix together, heat to 50-70°C and stir for 5 minutes to obtain a homogeneous resin system.

3. Mix 97 parts of 400 ^# epoxy, 2 parts of diphenyliodonium hexafluoroantimonate, and 1.5 parts of acetylacetone, mix together, heat to 50-70°C and stir for 5 minutes to obtain a homogeneous resin system.

4. Equipped with the same amount of main catalyst and co-catalyst as in Example 3, replace the epoxy with 97 parts of aliphatic epoxy B-63 and obtain a homogeneous resin system with the same operation method as above.

5. Take 97 parts of E54 epoxy, 2 parts of triphenylsulfonium hexafluoroantimonate, and 1.5 parts of acetylacetone, mix together and heat to 50-70°C, and stir for 5 minutes to obtain a homogeneous resin system.

6. Take 97 parts of E54 epoxy, 2 parts of 2-hydroxy-tetradecylphenyl ether base phenyliodonium hexafluoride , Mix and heat 1.5 parts of acetylacetone to 50-70°C and stir for 5 minutes to obtain a homogeneous resin system.

7. Replace the co-catalyst acetylacetone in Example 1 with ethyl acetoacetate, and keep the others unchanged, to obtain a resin system of the same quality.

Claims (2)

1. the single-component thermosetting epoxy resin system of being made up of Resins, epoxy and catalyzer is characterized in that, catalyzer comprises Primary Catalysts salt compounded of iodine or sulfosalt and synergistic catalyst active hydrogen supply body: R ₁Be one of following group :-CH ₃,-CH ₂CH ₃,-CH ₂CH ₂CH ₃R ₂Be one of following group :-CH ₃,-OCH ₃,-OCH ₂CH ₃The content of Primary Catalysts accounts for 1～10% (wt) of resin system gross weight, and the ratio of Primary Catalysts and synergistic catalyst is 1: 2～2: 1.

2. single-component thermosetting epoxy resin system according to claim 1 is characterized in that, Primary Catalysts is salt compounded of iodine or sulfosalt; The general structure of salt compounded of iodine is: R ₃-I ⁺-R ₄A ^-, R ₃And R ₄Be one of following group:

The general structure of sulfosalt is: R ₁, R ₂And R ₃Be one of following group: In salt compounded of iodine and the sulfosalt, negative ion A ^-Be one of following structure: S _bF ₆ ^-, A _SF ₆ ^-, PF ₆ ^-, BF ₄ ^-