Epoxy resin, curable resin composition, cured product thereof, and printed circuit board

Patent metadata

Field	Value
Publication number	US-9736926-B2
Application number	US-201314431522-A
Country	US
Kind code	B2
Filing date	Aug 29, 2013
Priority date	Sep 26, 2012
Publication date	Aug 15, 2017
Grant date	Aug 15, 2017

Abstract

The present invention provides a curable resin composition, a cured product of which has a small change in heat resistance after receiving a thermal history and a low thermal expansion property; a cured product of the curable resin composition; a printed circuit board having a small change in heat resistance; and an epoxy resin which imparts the characteristics described above. The epoxy resin is an epoxy resin which is obtained by polyglycidyl etherification of a reaction product formed from ortho-cresol, a β-naphthol compound, and formaldehyde and which includes as a necessary component, a dimer (x2, formula (1)), a trifunctional compound (x3, formula (2)), and a tetrafunctional compound (x4, formula (3)). The total content of those components is 65% or more in terms of the area rate in GPC measurement.

First claim

The invention claimed is:

1. An epoxy resin which is obtained by polyglycidyl etherification of a reaction product formed from ortho-cresol, a β-naphthol compound, and formaldehyde and which comprises as a necessary component,
a dimer (x2) represented by the following structural formula (1)

in the formula, R 1 and R 2 each independently represent a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or an alkoxy group having 1 to 4 carbon atoms, and G represents a glycidyl group);
a trifunctional compound (x3) represented by the following structural formula (2)

(in the formula, R 1 and R 2 each independently represent a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or an alkoxy group having 1 to 4 carbon atoms, and G represents a glycidyl group); and
a tetrafunctional compound (x4) represented by the following structural formula (3)

(in the formula, R 1 and R 2 each independently represent a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or an alkoxy group having 1 to 4 carbon atoms, and G represents a glycidyl group)
wherein the total content of those components is 65% or more in terms of the area rate in GPC measurement, and the content of the tetrafunctional compound (x4) is in a range of 10% to 40% in terms of the area rate in GPC measurement; and
a value of the molecular weight distribution (Mw/Mn) is in a range of 1.00 to 1.50.

2. The epoxy resin according to claim 1 , wherein the epoxy equivalent is in a range of 220 to 300 g/eq.

3. The epoxy resin according to claim 1 , wherein the softening point is in a range of 70° C. to 100° C.

4. A curable resin composition comprising as a necessary component: the epoxy resin according to claim 1 ; and a curing agent.

5. A printed circuit board obtained by a process comprising: impregnating a reinforcing substrate with a varnish resin composition formed by further blending an organic solvent with the curable resin composition according to claim 4 ; overlapping copper foil on the reinforcing substrate; and performing heat pressure bonding.

6. A cured product obtained by a curing reaction of the curable resin composition according to claim 4 .

7. The cured product according to claim 6 , wherein as for Tg measured by a viscoelasticity measurement apparatus, the difference in Tg (ΔTg) between a first measurement and a second measurement is 6° C. or less.

8. A method for manufacturing an epoxy resin according to claim 1 , the method comprising: performing a reaction between a β-naphthol compound and formaldehyde in the presence of an organic solvent and an alkaline catalyst and then performing a reaction by adding ortho-cresol in the presence of formaldehyde to obtain a cresol-naphthol resin (step 1); and then performing a reaction between the cresol-naphthol resin and an epihalohydrin (step 2) to obtain an epoxy resin.

9. The method for manufacturing an epoxy resin according to claim 8 , wherein the step 1 is performed under a temperature condition of 40° C. to 100° C.

10. A method for manufacturing an epoxy resin according to claim 1 , the method comprising: performing a reaction among ortho-cresol, a β-naphthol compound, and formaldehyde in the presence of an organic solvent and an alkaline catalyst to obtain a cresol-naphthol resin (step 1); and then performing a reaction between the cresol-naphthol resin and an epihalohydrin (step 2) to obtain an epoxy resin.

11. The method for manufacturing an epoxy resin according to claim 10 , wherein the step 1 is performed under a temperature condition of 40° C. to 100° C.

12. A curable resin composition comprising as a necessary component: the epoxy resin according to claim 2 ; and a curing agent.

13. A curable resin composition comprising as a necessary component: the epoxy resin according to claim 3 ; and a curing agent.

14. A cured product obtained by a curing reaction of the curable resin composition according to claim 12 .

15. The cured product according to claim 14 , wherein as for Tg measured by a viscoelasticity measurement apparatus, the difference in Tg (ΔTg) between a first measurement and a second measurement is 6° C. or less.

16. A printed circuit board obtained by a process comprising: impregnating a reinforcing substrate with a varnish resin composition formed by further blending an organic solvent with the curable resin composition according to claim 12 ; overlapping copper foil on the reinforcing substrate; and performing heat pressure bonding.

Assignees

• Dainippon Ink & Chemicals

Inventors

• Satou Yutaka

Classifications

• C08G59/32

  Epoxy compounds containing three or more epoxy groups · CPC title

• H05K1/0373

  containing additives, e.g. fillers (H05K1/036 takes precedence) · CPC title

• H05K3/00

  Apparatus or processes for manufacturing printed circuits · CPC title

• H05K1/0326

  containing O · CPC title

• H05K1/09

  Use of materials for the {conductive, e.g. } metallic pattern · CPC title