One-pack epoxy resin composition, one-pack corrosion resistant paint composition, and coating method using said compositions

• US 6,045,873 A
• Filed: 02/18/1998
• Issued: 04/04/2000
• Est. Priority Date: 08/23/1995
• Status: Expired due to Fees

• Current Assignee: Kansai Paint Company Limited
• Original Assignee: Kansai Paint Company Limited
• Inventors: Hamamura, Toshihiro, Adachi, Yoshimitsu
• Primary Examiner(s): Marquis, Melvyn I.
• Assistant Examiner(s): AYLWARD, DAVID E
• Application Number:
  US09/029,096
• Time in Patent Office: 776 Days
• Field of Search: 523/400, 523/442, 523/457, 523/458, 523/465, 525/522, 525/526, 525/528, 525/529, 525/530, 525/531, 528/103, 427/410
• US Class Current: 427/410
• CPC Class Codes: C08G 59/4042 Imines; Imides
• CPC Class Codes: C08L 2666/54 Inorganic substances
• CPC Class Codes: C09D 163/00 Coating compositions based on epoxy resins; Coating compositions based on derivatives of epoxy resins
• CPC Class Codes: C09D 5/106 containing Zn

Abstract

The present invention provides:

(1) a one-packed epoxy resin composition comprising

(A) an epoxy resin having two or more epoxy groups in its molecule and a number average molecular weight of 250 to 4,500,

(B) a ketimine compound,

(C) a dehydrating agent, and

(D) at least one modified epoxy resin (d-1) selected among urethane-modified epoxy resins, amine-modified epoxy resins and dimer-modified epoxy resins and/or a resin (d-2) which has a softening point of 60° C. or above and is at least one member selected among xylene resins, ketone resins, coumarone resins and petroleum resins;

(2) a one-packed anticorrosive paint composition comprising the above one-packed epoxy resin composition and (E) a zinc dust in such an amount as to be present in a proportion of 20 to 95 wt. % in the heat-cured coating film; and

(3) a coating method comprising the steps of undercoating the surface of a substrate and conducting topcoating, wherein the above one-packed epoxy resin composition or the above anticorrosive paint composition is used as the undercoating composition.

Claims

1. A one-packed epoxy resin composition comprising:

(A) an epoxy resin having two or more epoxy groups in the resin molecule and said epoxy resin having a number average molecular weight of 250 to 4,500,

(B) a ketimine compound,

(C) a dehydrating agent, and

(D) at least one epoxy resin (d-1) selected among urethane-modified epoxy resins prepared by reacting a polyisocyanate or monoisocyanate compound with an amine-added epoxy resin;

amine-modified epoxy resins obtained by addition-polymerizing an epoxy resin with a polyvalent phenol such as bisphenol A to obtain an epoxy resin having a desired molecular weight and then reacting the obtained resin with an alkanol amine; and

dimer acid-modified epoxy resins obtained by addition-polymerizing a polyvalent phenol such as bisphenol A and an adduct of an epoxy resin with a dimer acid; and

/or a resin (d-2) which has a softening point of 60°

C. or above and is at least one member selected among xylene resins obtained by reacting meta-xylene with formaldehyde using a catalyst such as sulfuric acid and further reacting the obtained xylene resin with a phenol or a rosin;

ketone resins obtained by reacting a ketone such as cyclohexanone with a formaldehyde using a catalyst such as sulfuric acid;

coumarone resins obtained by refining a 160 to 180°

C. distillate fraction of naphtha and polymerizing the refined product by heating or with sulfuric acid; and

petroleum resins obtained by cationically polymerizing, with a Friedel-Crafts catalyst, C₅ or higher olefin residues from oil cracking.

2. A composition according to claim 1 which contains the ketimine compound (B) in such a proportion that the amount of the active hydrogen in the ketimine compound is 0.5 to 5.0 equivalents per equivalent of the epoxy group in the epoxy resin (A).

3. A composition according to claim 1 which contains the dehydrating agent (C) in a proportion of 0.1 to 25 wt. parts per 100 wt. parts of the total solid content weight of the components (A), (B) and (D) of the composition.

4. A composition according to claim 1 which contains the resin (d-1) as the component (D) in a proportion of 5 to 95 wt. parts per 100 wt. parts of the epoxy resin (A), in terms of resin solid content.

5. A composition according to claim 1 which contains the resin (d-2) as the component (D) in a proportion of 5 to 70 wt. parts per 100 wt. parts of the epoxy resin (A), in terms of resin solid content.

7. A coating method comprising the steps of:

undercoating the surface of a substrate with the one-packed epoxy resin composition according to claim 1; and

applying a topcoating composition.

6. A one-packed anticorrosive paint composition comprising:

(A) an epoxy resin having two or more epoxy groups in the resin molecule and said epoxy resin having a number average molecular weight of 250 to 4,500,

(B) a ketimine compound,

(C) a dehydrating agent, and

(D) at least one epoxy resin (d-1) selected among urethane-modified epoxy resins prepared by reacting a polyisocyanate or monoisocyanate compound with an amine-added epoxy resin;

amine-modified epoxy resins obtained by addition-polymerizing an epoxy resin with a polyvalent phenol such as bisphenol A to obtain an epooxy resin having a desired molecular weight and then reacting the obtained resin with an alkanol amine; and

dimer acid-modified epoxy resins obtained by addition-polymerizing a polyvalent phenol such as bisphenol A and an adduct of an epoxy resin with a dimer acid; and

/or a resin (d-2) which has a softening point of 60°

C. or above and is at least one member selected among xylene resins obtained by reacting meta-xylene with formaldehyde using a catalyst such as sulfuric acid and further reacting the obtained xylene resin with a phenol or a rosin;

ketone resins obtained by reacting a ketone such as cyclohexanone with a formaldehyde using a catalyst such as sulfuric acid;

coumarone resins obtained by refining a 160 to 180°

C. distillate fraction of naphtha and polymerizing the refined product by heating or with sulfuric acid; and

petroleum resins obtained by cationically polmerizing, with a Friedel-Crafts catalyst C₅ or higher olefin residues from oil cracking, and

(E) a zinc dust in such an amount as to be present in a proportion of 20 to 95 wt. % in the heat-cured coating film.

8. A coating method comprising the steps of:

undercoating the surface of a substrate with the one-packed anticorrosive paint composition according to claim 6; and

applying a topcoating composition.