Curing agent for powder coatings, powder coating composition comprising said curing agent, and powder coating film

• US 6,111,017 A
• Filed: 05/19/1998
• Issued: 08/29/2000
• Est. Priority Date: 05/19/1997
• Status: Expired due to Fees

• Current Assignee: Nisshinbo Industries, Inc. (Kawasaki Heavy Industries Limited)
• Original Assignee: Nisshinbo Industries, Inc. (Kawasaki Heavy Industries Limited)
• Inventors: Suzuki, Shigekazu, Yamane, Takeshi, Takahashi, Ikuo, Imashiro, Yasuo, Horie, Naofumi
• Primary Examiner(s): Gorr, Rachel
• Application Number:
  US09/081,050
• Time in Patent Office: 833 Days
• Field of Search: 528/49, 528/45, 528/44, 528/69, 525/123, 525/440
• US Class Current: 525/123
• CPC Class Codes: C08G 18/025 the polymeric products containing carbodiimide groups
• CPC Class Codes: C08G 18/423 containing cycloaliphatic groups
• CPC Class Codes: C08G 18/71 Monoisocyanates or monoisothiocyanates
• CPC Class Codes: C08G 18/7678 containing condensed aromatic rings
• CPC Class Codes: C08G 18/797 containing carbodiimide and/or uretone-imine groups
• CPC Class Codes: C08G 18/8064 with monohydroxy compounds
• CPC Class Codes: C08G 18/808 Monoamines
• CPC Class Codes: C08G 2150/20 Compositions for powder coatings
• CPC Class Codes: C09D 179/00 Coating compositions based on macromolecular compounds obtained by reactions forming in the main chain of the macromolecule a linkage containing nitrogen, with or without oxygen, or carbon only, not provided for in groups C09D161/00 - C09D177/00

Abstract

The present invention provides:

(A) a curing agent for powder coatings, which comprises, as a main component, a carbodiimide compound represented by the following general formula (1), (2) or (3):

OCN--R.sub.1 --(NCN--R.sub.2).sub.n1 --NCO                 (1)

R.sub.3 --NCN--R.sub.4 --(NCN--R.sub.5).sub.n2 --NCN--R.sub.6(2)

R.sub.7 --R.sub.8 --(NCN--R.sub.9).sub.n3 --R.sub.10       (3)

(B) a powder coating composition comprising:

at least one kind of the above curing agent (A) for powder coating, and

a bifunctional resin compound having a functional group reactive with carbodiimide group; and

(C) powder coating film, which is obtained by reacting and curing at least one kind of the above curing agent (A) for powder coating, and a bifunctional resin compound having a functional group reactive with carbodiimide group.

Claims

1. A powder coating composition comprising:

a curing agent for powder coating, which comprises, as a main component, a carbodiimide compound represented by the following formula (1);

space="preserve" listing-type="equation">OCN--R.sub.1 --(NCN--R.sub.2).sub.n1 --NCO (1)

wherein R₁ and R₂ may be the same or different and are each a residue of an aliphatic, alicyclic, or aromatic diisocyanate; and

n1 is an integer of 2 to 50, and

a bifunctional coating resin compound having a functional group reactive with a carbodiimide group and selected from the group consisting of an epoxy resin, an epoxy/polyester resin, a polyester resin;

a polyester/polyurethane resin, and an acrylic resin,

said powder coating composition being curable at a temperature of 100 to 150°

C.

2. A powder coating film, which is obtained by reacting and curing a curing agent for powder coating, which comprises, as a main component, a carbodiimide compound represented by the following formula (1):

space="preserve" listing-type="equation">OCN--R.sub.1 --(NCN--R.sub.2).sub.n1 --NCO (1)

wherein R₁ and R₂ may be the same or different and are each a residue of an aliphatic, alicyclic, or aromatic diisocyanate; and

n1 is an integer of 2 to 50, and

a bifunctional resin compound having a functional group reactive with a carbodiimide group and selected from the group consisting of an epoxy resin, an epoxy/polyester resin, a polyester resin;

a polyester/polyurethane resin, and an acrylic resin,

said powder coating composition being curable at a temperature of 100 to 150°

C.

3. A powder coating composition comprising:

a curing agent for powder coating, which comprises, as a main component, a carbodiimide compound represented by the following formula (2);

space="preserve" listing-type="equation">R.sub.3 --NCN--R.sub.4 --(NCN--R.sub.5).sub.n2 --NCN--R.sub.6(

     2)

wherein R₄ and R₅ may be the same or different and are each a residue of an aliphatic, alicyclic, or aromatic diisocyanate;

R₃ and R₆ may be the same or different and are each a residue of an aliphatic, alicyclic or aromatic monoisocyanate; and

n2 is an integer of 0 to 48, and

a bifunctional coating resin compound having a functional group reactive with a carbodiimide group and selected from the group consisting of an epoxy resin, an epoxy/polyester resin, a polyester resin;

a polyester/polyurethane resin, and an acrylic resin,

said powder coating composition being curable at a temperature of 100 to 150°

C.

4. A powder coating composition comprising:

a curing agent for powder coating, which comprises, as a main component, a carbodiimide compound represented by the following formula (3);

space="preserve" listing-type="equation">R.sub.7 --R.sub.8 --(NCN--R.sub.9).sub.n3 --R.sub.10 (

     3)

wherein R₈ and R₉ may be the same or different and are each a residue of an aliphatic, alicyclic, or aromatic diisocyanate;

R₇ and R₁₀ may be the same or different and are each a residue formed by the reaction of an isocyanate group with an alcohol, an amine, a carboxylic acid or an acid anhydride; and

n3 is an integer of 2 to 50, and

a bifunctional coating resin compound having a functional group reactive with a carbodiimide group and selected from the group consisting of an epoxy resin, an epoxy/polyester resin, a polyester resin;

a polyester/polyurethane resin, and an acrylic resin,

said powder coating composition being curable at a temperature of 100 to 150°

C.

5. A powder coating film, which is obtained by reacting and curing a curing agent for powder coating, which comprises, as a main component, a carbodiimide compound represented by the following formula (2):

space="preserve" listing-type="equation">R.sub.3 --NCN--R.sub.4 --(NCN--R.sub.5).sub.n2 --NCN--R.sub.6(

     2)

wherein R₄ and R₅ may be the same or different and are each a residue of an aliphatic, alicyclic, or aromatic diisocyanate;

R₃ and R₆ may be the same or different and are each a residue of an aliphatic, alicyclic or aromatic monoisocyanate; and

n2 is an integer of 0 to 48, and

a bifunctional resin compound having a functional group reactive with a carbodiimide group and selected from the group consisting of an epoxy resin, an epoxy/polyester resin, a polyester resin;

a polyester/polyurethane resin, and an acrylic resin, said powder coating film being curable at a temperature of 100 to 150°

C.

6. A powder coating film, which is obtained by reacting and curing a curing agent for powder coating, which comprises, as a main component, a carbodiimide compound represented by the following formula (3):

space="preserve" listing-type="equation">R.sub.7 --R.sub.8 --(NCN--R.sub.9).sub.n3 --R.sub.10 (

     3)

wherein R₈ and R₉ may be the same or different and are each a residue of an aliphatic, alicyclic, or aromatic diisocyanate;

R₇ and R₁₀ may be the same or different and are each a residue formed by the reaction of an isocyanate group with an alcohol, an amine, a carboxylic acid or an acid anhydride; and

n3 is an integer of 2 to 50, and

a bifunctional resin compound having a functional group reactive with a carbodiimide group and selected from the group consisting of an epoxy resin, a epoxy/polyester resin, a polyester resin;

a polyester/polyurethane resin, and an acrylic resin,

said powder coating film being curable at a temperature of 100 to 150°

C.