Epoxy resins incorporated with imidazole/chromium acetylacetonate and composites thereof
AssigneeNational Science Council
InventorKing-Fu Lin
Life of this patent
Estimating the term…
Abstract
The present invention provides a curable epoxy resin composition, which includes an epoxy resin; from 10 to 60 percent by weight of the epoxy resin of an amine curing agent; from 0.1 to 5 percent by weight of the epoxy resin of an imidazole accelerator; and from 0.01 to 5 percent by mole of the epoxy resin of chromium acetylacetonate (Cr(acac).sub.3). The resultant cured epoxy resin prepared from the epoxy resin composition of the present invention demonstrates improved fracture toughness. Also, the interlaminar fracture energy of the resultant graphite/epoxy laminate prepared from the cured epoxy resin of the present invention is greater than that of the conventional graphite/epoxy laminate.
Claims31
A curable epoxy resin composition, comprising:
- an epoxy resin;
- from 10 to 60 percent by weight of the epoxy resin of an amine curing agent;
- from 0.1 to 5 percent by weight of the epoxy resin of an imidazole accelerator;
- and
- from 0.01 to 5 percent by mole of the epoxy resin of chromium acetylacetonate (Cr(acac).sub.3),
- wherein the imidazole accelerator has the formula ##STR2## wherein R.sup.1 is selected from the group consisting of an alkyl having from 11 to 25 carbon atoms and a phenyl, and R.sup.2 is selected from the group consisting of H, an alkyl having from 1 to 25 carbon atoms, and a phenyl.
A curable epoxy resin composite composition, comprising:
- an epoxy resin;
- from 10 to 60 percent by weight of the epoxy resin of an amine curing agent;
- from 0.1 to 5 percent by weight of the epoxy resin of an imidazole accelerator;
- from 0.01 to 5 percent by mole of the epoxy resin of chromium acetylacetonate (Cr(acac).sub.3);
- and
- a fiber,
- wherein the imidazole accelerator has the formula ##STR3## wherein R.sup.1 is selected from the group consisting of an alkyl having from 11 to 25 carbon atoms and a phenyl, and R.sup.2 is selected from the group consisting of H, an alkyl having from 1 to 25 carbon atoms, and a phenyl.
A process for preparing a cured epoxy resin, comprising:
- a) providing an epoxy resin;
- b) adding from 0.01 to 5 percent by mole of the epoxy resin of chromium acetylacetonate to the epoxy resin;
- c) adding from 10 to 60 percent by weight of the epoxy resin of an amine curing agent, then adding from 0.1 to 5 percent by weight of the epoxy resin of an imidazole accelerator to the epoxy resin to form a resin mixture;
- and
- d) curing the resin mixture at a temperature in a range of from 100.degree. C. to 200.degree. C.,
- wherein the imidazole accelerator has the formula ##STR4## wherein R.sup.1 is selected from the group consisting of an alkyl having from 11 to 25 carbon atoms and a phenyl, and R.sup.2 is selected from the group consisting of H, an alkyl having from 1 to 25 carbon atoms, and a phenyl.
A process for preparing a cured epoxy resin, comprising:
- a) providing an epoxy resin;
- b) adding from 0.01 to 5 percent by mole of the epoxy resin of chromium acetylacetonate to the epoxy resin, and stirring at a temperature in a range of from 50.degree. C. to 100.degree. C. to form a resin pre-solution;
- c) adding from 10 to 60 percent by weight of the epoxy resin of an amine curing agent and then adding from 0.1 to 5 percent by weight of the epoxy resin of an imidazole accelerator to the resin pre-solution to form a resin solution;
- and
- d) curing the resin solution at a temperature in a range of from 100.degree. C. to 200.degree. C.,
- wherein the imidazole accelerator has the formula ##STR5## wherein R.sup.1 is selected from the group consisting of an alkyl having from 11 to 25 carbon atoms and a phenyl, and R.sup.2 is selected from the group consisting of H, an alkyl having from 1 to 25 carbon atoms, and a phenyl.
A process for preparing a cured epoxy resin, comprising:
- a) providing an epoxy resin;
- b) dissolving from 0.01 to 5 percent by mole of the epoxy resin of chromium acetylacetonate in a solvent at room temperature to form a chromium acetylacetonate solution;
- c) adding the chromium acetylacetonate solution to the epoxy resin;
- d) removing the solvent;
- e) adding from 10 to 60 percent by weight of the epoxy resin of an amine curing agent, and then adding from 0.1 to 5 percent by weight of the epoxy resin of an imidazole accelerator to the solvent-removed chromium/epoxy resin solution to form a resin mixture;
- and
- d) curing the resin mixture obtained in step e) at a temperature in a range of from 100.degree. C. to 200.degree. C.,
- wherein the imidazole accelerator has the formula ##STR6## wherein R.sup.1 is selected from the group consisting of an alkyl having from 11 to 25 carbon atoms and a phenyl, and R.sup.2 is selected from the group consisting of H, an alkyl having from 1 to 25 carbon atoms, and a phenyl.
A curable epoxy resin composition, comprising:
- a tetrafunctional epoxy resin;
- from 10 to 60 percent by weight of the epoxy resin of an amine curing agent;
- from 0.1 to 5 percent by weight of the epoxy resin of 2-undecyl-imidazole;
- and
- from 0.01 to 5 percent by mole of the epoxy resin of chromium acetylacetonate.
A curable epoxy resin composite composition, comprising:
- a tetrafunctional epoxy resin;
- from 10 to 60 percent by weight of the epoxy resin of an amine curing agent;
- from 0.1 to 5 percent by weight of the epoxy resin of 2-undecyl-imidazole;
- from 0.01 to 5 percent by mole of the epoxy resin of chromium acetylacetonate;
- and
- a carbon fiber.
Dependencies are inferred from the claim text.