Method of preparing a latent hardener with improved storage stability through a dry surface treatment

Patent metadata

Field	Value
Publication number	US-11286334-B2
Application number	US-202016788519-A
Country	US
Kind code	B2
Filing date	Feb 12, 2020
Priority date	Nov 26, 2019
Publication date	Mar 29, 2022
Grant date	Mar 29, 2022

Abstract

A method for preparing a latent hardener includes, in the order recited, introducing a hardener into a dry mixer that is a high-energy-type mixer; injecting carbon dioxide gas or an inert gas into the dry mixer; and mechanochemically deactivating only a surface of the hardener using the dry mixer. The hardener may be an amine-based adduct, an imidazole-based adduct, dicyandiamide, a dihydride-based compound, a dichlorophenyl dimethylurea compound and combinations thereof. The inert gas may be helium, nitrogen, argon, neon, krypton, and combinations thereof.

First claim

What is claimed is:

1. A method for preparing a latent hardener, the method consisting essentially of, in the order recited:
introducing a hardener into a dry mixer that is a high-energy-type mixer;
injecting carbon dioxide gas or an inert gas into the dry mixer; and
mechanochemically deactivating only a surface of the hardener using the dry mixer.

2. The method of claim 1 , wherein the hardener is selected from the group consisting of an amine-based adduct, an imidazole-based adduct, dicyandiamide, a dihydride-based compound, a dichlorophenyl dimethylurea compound, and combinations thereof.

3. The method of claim 1 , wherein the inert gas is selected from the group consisting of helium, nitrogen, argon, neon, krypton, and combinations thereof.

4. The method of claim 1 , wherein the carbon dioxide or inert gas is injected into the dry mixer at a flow rate of 0.1 to 10 L/min, and
mechanochemically deactivating only the surface of the hardener is performed for a time ranging from 1 to 240 minutes.

5. The method of claim 1 , wherein the dry mixer comprises a vessel having an adjustable temperature, a rotating inner vessel, a pressure-applying arm, and a scraper, and
wherein the method is performed by a condition selected from the group consisting of a rotation speed of the rotating inner vessel, a gap between the rotating inner vessel and the pressure-applying arm, a type of gas, a gas inflow amount, temperature, and combinations thereof.

6. The method of claim 5 , wherein the rotation speed of the rotating inner vessel is 20 to 15,000 rpm, the gap between the rotating inner vessel and the pressure-applying arm is 0.2 to 10 mm, and the temperature is 20 to 60° C.

Assignees

• Korea Inst Sci & Tech

Inventors

• Park Jong Hyuk
• Park Min
• Kim Tae Ann
• Kim Jongwon
• Jee Sung Min

Classifications

• C08G59/18

  Macromolecules obtained by polymerising compounds containing more than one epoxy group per molecule using curing agents or catalysts which react with the epoxy groups {; e.g. general methods of curing} · CPC title

• C08G59/245

  aromatic · CPC title

• C07D247/02 Primary

  having the nitrogen atoms in positions 1 and 3 · CPC title

• C08G59/188

  using encapsulated compounds · CPC title

• C07C277/00

  Preparation of guanidine or its derivatives, i.e. compounds containing the group [IMAGE cpc-sch-C07C-0970.gif], the singly-bound nitrogen atoms not being part of nitro or nitroso groups · CPC title