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CN-122011681-A - Anhydride-free epoxy resin and curing molding method and application thereof

CN122011681ACN 122011681 ACN122011681 ACN 122011681ACN-122011681-A

Abstract

The invention relates to the technical field of insulating materials of electrical equipment, in particular to anhydride-free epoxy resin, a curing molding method and application thereof, and the preparation raw materials comprise, by weight, 65% -80% of alicyclic epoxy resin, 19% -30% of dimer acid modified epoxy resin, 4% -10% of hydrogenated epoxy resin, 0.5% -5% of latent curing agent, 0.1% -0.5% of accelerator and the balance of synergistic accelerator. The anhydride-free epoxy resin prepared by the invention has low viscosity, can fully enter the gap between the glass fiber tape winding layers to form a uniform and compact insulating layer, does not contain anhydride, and has the advantages of difficult moisture absorption, long-time glass fiber winding process, simple winding operation, smaller odor, environmental protection and the like.

Inventors

  • WU QI

Assignees

  • 上海江天高分子材料有限公司

Dates

Publication Date
20260512
Application Date
20260331

Claims (10)

  1. 1. The anhydride-free epoxy resin is characterized by comprising the following preparation raw materials in percentage by weight: 65% -80% of alicyclic epoxy resin 19-30% Of dimer acid modified epoxy resin 4% -10% Of hydrogenated epoxy resin 0.5-5% Of latent curing agent 0.1 To 0.5 percent of accelerator The synergistic accelerator makes up the balance.
  2. 2. The anhydride-free epoxy resin of claim 1, wherein the cycloaliphatic epoxy resin comprises at least one of 3, 4-epoxycyclohexyl formate and bis (7-oxabicyclo [4.1.0] 3-heptylmethyl) adipate.
  3. 3. The anhydride-free epoxy resin according to claim 1, wherein the dimer acid-modified epoxy resin has a viscosity of 400-900cps at 25 ℃ and an epoxy equivalent of 390-470g/eq.
  4. 4. The anhydride-free epoxy resin of claim 1, wherein the hydrogenated epoxy resin comprises a hydrogenated bisphenol a epoxy resin.
  5. 5. The anhydride-free epoxy resin of claim 1 wherein the latent curative comprises a liquid dicyandiamide latent curative.
  6. 6. The anhydride-free epoxy resin of claim 1, wherein the accelerator comprises a tertiary amine accelerator ‌.
  7. 7. The anhydride-free epoxy resin of claim 1, wherein the co-accelerator comprises at least one of a phenolic co-accelerator and an alcoholic co-accelerator.
  8. 8. A method of curing and shaping an anhydride-free epoxy resin as claimed in any one of claims 1 to 7, comprising at least the steps of: The anhydride-free epoxy resin is subjected to gradient heating, curing and forming within the temperature range of 80-180 ℃.
  9. 9. The method according to claim 8, wherein the step of gradient heating is specifically performed by curing at 80 ℃ to 90 ℃ for 5h hours at 120 ℃, curing at 150 ℃ for 5h, and finally curing at 180 ℃ for 10 h.
  10. 10. Use of an anhydride-free epoxy resin according to any one of claims 1-7 in an insulation system of an electrical device.

Description

Anhydride-free epoxy resin and curing molding method and application thereof Technical Field The invention relates to the technical field of insulating materials of electrical equipment, in particular to anhydride-free epoxy resin, a curing molding method and application thereof. Background The dry reactor has the advantages of small weight, low cost, simple maintenance, long service life and the like, and is widely applied to power systems. At present, the exterior of many dry-type reactor coils is required to be wound and encapsulated by glass fiber bundles impregnated with epoxy resin, and the formed solidified product has good insulation performance as a whole. The epoxy resin of the existing reactor is mainly divided into two types, wherein the first type is an epoxy-anhydride curing system, for example, the Chinese patent application CN121450064A, the formula mainly comprises epoxy resin, nearly half of anhydride curing agent and trace curing accelerator, and the second type mainly comprises epoxy resin and latent catalytic curing agent. Because the first epoxy resin composition system contains the acid anhydride curing agent, when the long-time glass fiber winding process is carried out, the acid anhydride curing agent is easy to absorb moisture, so that the curing process is uneven, the cured insulating product has high brittleness and is easy to generate microcracks, the local temperature rise is easy to be overhigh, the insulating performance is poor, and even the inter-turn insulation breakdown phenomenon occurs to serious cases. Therefore, it is important to prepare a second type of anhydride-free epoxy resin to reduce the moisture absorption of the material and to enhance the weatherability of the resin during curing. Disclosure of Invention In order to solve the problems in the prior art, the first aspect of the invention provides anhydride-free epoxy resin, which comprises the following preparation raw materials in percentage by weight: 65% -80% of alicyclic epoxy resin 19-30% Of dimer acid modified epoxy resin 4% -10% Of hydrogenated epoxy resin 0.5-5% Of latent curing agent 0.1 To 0.5 percent of accelerator The synergistic accelerator makes up the balance. The invention completely eliminates the traditional anhydride curing agent, adopts the latent curing agent to replace, and the latent curing agent is chemically inert at normal temperature, and only decomposes at high temperature to generate active amine substances to initiate curing, thereby thoroughly avoiding the problem of moisture absorption and ensuring the stable and controllable curing process. In some embodiments, the cycloaliphatic epoxy resin comprises at least one of 3, 4-epoxycyclohexyl formate, bis (7-oxabicyclo [4.1.0] 3-heptylmethyl) adipate. Optionally, the cycloaliphatic epoxy resin is 3, 4-epoxycyclohexyl formate. Alternatively, the cycloaliphatic epoxy resin is 3, 4-epoxycyclohexyl formate and bis (7-oxabicyclo [4.1.0] 3-heptylmethyl) adipate, the bis (7-oxabicyclo [4.1.0] 3-heptylmethyl) adipate being up to 50 weight percent of the cycloaliphatic epoxy resin. Optionally, the alicyclic epoxy resin is 3, 4-epoxycyclohexyl formate and bis (7-oxabicyclo [4.1.0] 3-heptylmethyl) adipate with a mass ratio of 1:1. In some embodiments, the dimer acid modified epoxy resin has a viscosity of 400 to 900cps at 25 ℃ and an epoxy equivalent weight of 390 to 470g/eq. Optionally, the dimer acid-modified epoxy resin includes a C18-unsaturated fatty acid dimer diglycidyl ether. Alternatively, the model of the C18-unsaturated fatty acid dimer diglycidyl ether is YD-171, available from Kunshan chemical Co., ltd. The invention combines the low-viscosity alicyclic epoxy resin and the dimer acid modified epoxy resin for use, and can realize the obvious reduction of the system viscosity and the optimization of wettability. The alicyclic epoxy resin has a rigid structure but low viscosity, and the C18 soft chain segment of the dimer acid modified epoxy resin can further reduce the viscosity of the system and enhance the fluidity, and the molecular chain of the resin is easier to penetrate into gaps among glass fiber monofilaments by the synergistic effect of the two, so that a uniform and compact insulating layer is formed. In some embodiments, the hydrogenated epoxy resin comprises a hydrogenated bisphenol a epoxy resin. Alternatively, the hydrogenated bisphenol A epoxy resin comprises 4,4- (1-methylethylinder) dicyclohexyl diglycerol ether ester. Alternatively, the hydrogenated bisphenol A epoxy resin is model XY518, from Anhui New technology Co., ltd. The invention improves the brittleness of the cured product and improves the mechanical property by introducing the hydrogenated bisphenol A epoxy resin while maintaining high crosslinking density. The saturated fatty chain structure of hydrogenated bisphenol A can effectively disperse stress concentration points and reduce brittle fracture, and meanwhile, the flexibility of the molecular chai