Corrosion and alkali-resistant compositions and methods for using the same

• US 20050027042A1
• Filed: 06/30/2004
• Published: 02/03/2005
• Est. Priority Date: 11/06/2002
• Status: Active Grant

• Current Assignee: PPG Industries Ohio Incorporated (Nouryon BV)
• Original Assignee: PPG Industries Ohio Incorporated (Nouryon BV)
• Inventors: Pawlik, Michael J., Perrine, Steven D., Jones, Dennis W., Nugent, Richard M. Jr., Gray, Ralph C.
• Granted Patent: US 7,282,266 B2
• Time in Patent Office: Days
• US Class Current: 523/400
• CPC Class Codes: C08G 59/1488 containing phosphorus
• CPC Class Codes: C08G 59/4071 phosphorus containing compounds
• CPC Class Codes: C08L 2666/16 Addition or condensation polymers of aldehydes or ketones according to C08L59/00 - C08L61/00; Derivatives thereof
• CPC Class Codes: C08L 2666/40 Phosphorus-containing compounds
• CPC Class Codes: C09D 163/00 Coating compositions based on epoxy resins; Coating compositions based on derivatives of epoxy resins
• CPC Class Codes: C09D 5/08 Anti-corrosive paints
• CPC Class Codes: Y10T 428/265 1 mil or less
• CPC Class Codes: Y10T 428/31511 Of epoxy ether
• CPC Class Codes: Y10T 428/31515 As intermediate layer
• CPC Class Codes: Y10T 428/31522 Next to metal
• CPC Class Codes: Y10T 428/31529 Next to metal
• CPC Class Codes: Y10T 428/31678 Of metal

Abstract

A corrosion resistant, alkali resistant coating composition is disclosed. The composition comprises a binder comprising a reaction product of an epoxy-containing material and a phosphorus-containing material together with a curing agent. Aminoplasts, especially melamine-based aminoplasts, are particularly suitable curing agents. A source of silicon can optionally be included. The compositions also provide excellent adhesion and can be used with or without a weldable primer. The compositions are applied to and cured on a metal substrate.

Claims

1-42. -42. (canceled).

43. A composition comprising:

a) a reaction product of one or more epoxy-containing materials and one or more phosphorus-containing materials;

b) a curing agent; and

c) elemental silicon,

wherein the composition is substantially free of conductive pigments and wherein the equivalent ratio of the phosphorous-containing material to epoxy-containing material is between about 0.3 and 5;

1.

44. The composition of claim 43, wherein the weight percent of (a) is from 50 to 100, based on the total weight of the composition.

45. The composition of claim 43, wherein the weight percent of (b) is from 5 to 25, based on the total weight of (a) and (b).

46. The composition of claim 43, wherein the weight percent of (c) is from 1.0 to 30, based on the total weight of the composition.

47. The composition of claim 43, wherein the weight ratio of (c) to (b) is from 0.01 to 1.0.

48. A coating layer combination comprising an anti-corrosion layer formed from the composition of claim 43, directly adjacent to a weldable coating layer comprising an electroconductive pigment and a binder.

61. The composition of claim 43, wherein the epoxy-containing material is a polyglycidal ether of a polyhydric phenol.

62. The composition of claim 61, wherein the polyhydric phenol is Bisphenol A.

63. The composition of claim 43, wherein the number average molecular weight of the epoxy-containing material is 220 to 25,000, as determined by multiplying the epoxy equivalent by the epoxy functionality.

64. The composition of claim 63, wherein the molecular weight of the epoxy-containing material is 220 to 4500.

65. The composition of claim 43, wherein the phosphorous-containing material is selected from the group consisting of phosphoric acid, a phosphonic acid, and phosphorous acid.

66. The composition of claim 43, wherein the curing agent is selected from the group consisting of aminoplast resins, polyisocyanates, polyacids, organometallic complexed materials, polyamines, and polyamides.

67. The composition of claim 66, wherein the curing agent is an aminoplast.

68. The composition of claim 67, wherein the aminoplast is a melamine-formaldehyde condensate.

69. The composition of claim 68, wherein the melamine-formaldehyde condensate comprises at least 40 weight percent of imino groups.

70. The composition of claim 43, wherein the number average molecular weight of a) is from 1000 to 5000.

71. The composition of claim 43, further comprising one or more corrosion resistant pigments.

72. The composition of claim 43, wherein said composition is aqueous-based.

73. The composition of claim 43, wherein said composition is solvent-based.

49. A weldable, corrosion resistant layer deposited on a substrate, wherein the weldable layer provides alkaline resistance to the substrate, is substantially free of conductive pigments, and comprising:

a) a cured reaction product of (i) a reaction product of at least one epoxy-functional material and at least one phosphorus-containing material, and (ii) a curing agent; and

b) elemental silicon.

50. The layer of claim 49, wherein the epoxy-containing material is a polyglycidyl ether of a polyhydric phenol.

51. The composition of claim 50, wherein the polyhydric phenol is Bisphenol A.

52. The composition of claim 49, wherein the number average molecular weight of the epoxy-containing material is 220 to 25,000, as determined by multiplying the epoxy equivalent by the epoxy functionality.

53. The composition of claim 49, wherein the phosphorus-containing material is selected from the group consisting of phosphoric acid, a phosphonic acid, and phosphorous acid.

54. The composition of claim 49, wherein the curing agent is selected from the group consisting of aminoplast resins, polyisocyanates, polyacids, organometallic complexed materials, polyamines, and polyamides.

55. The composition of claim 54, wherein the curing agent is an aminoplast.

56. The composition of claim 55, wherein the aminoplast is a melamine-formaldehyde condensate.

57. The composition of claim 56, wherein the melamine-formaldehyde condensate comprises at least 40 weight percent of imino groups.

58. The composition of claim 49, wherein the number average molecular weight of a) is from 1000 to 5000.

59. A weldable, corrosion resistant layer deposited on a substrate, wherein the weldable layer is of a thickness to provide corrosion resistance without inhibiting welding, is substantially free of conductive pigments, and comprises

a) the cured reaction product of (i) at least one epoxy-functional material and at least one phosphorus-containing material, and (ii) a curing agent;

and

b) elemental silicon

wherein the equivalent ratio of the phosphorous-containing material to epoxy-functional material is between 0.3 and 5;

1.

60. The layer of claim 59, wherein said layer is greater than 0.1 micron and less than 1.0 micron.

74. The layer of claim 59, wherein the epoxy-functional material is a polyglycidyl ether of a polyhydric phenol.

75. The layer of claim 74, wherein the polyhydric phenol is Bisphenol A.

76. The layer of claim 59, wherein the number average molecular weight of the epoxy-functional material is 220 to 25,000, as determined by multiplying the epoxy equivalent by the epoxy functionality.

77. The layer of claim 76, wherein the molecular weight of the epoxy-functional material is 220 to 4500.

78. The layer of claim 59, wherein the phosphorous-containing material is selected from the group consisting of phosphoric acid, a phosphonic acid, and phosphorous acid.

79. The layer of claim 59, wherein the curing agent is selected from the group consisting of aminoplast resins, polyisocyanates, polyacids, organometallic complexed materials, polyamines, and polyamides.

80. The layer of claim 79, wherein the curing agent is an aminoplast.

81. The layer of claim 80, wherein the aminoplast is a melamine-formaldehyde condensate.

82. The layer of claim 81, wherein the melamine-formaldehyde condensate comprises at least 40 weight percent of imino groups.

83. The layer of claim 59, wherein the number average molecular weight of a) is from 1000 to 5000.

84. The layer of claim 59, wherein the weight percent of (a) is from 50 to 100, based on the total weight of the composition.

85. The layer of claim 59, wherein the weight percent of (b) is from 5 to 25, based on the total weight of (a) and (b).

86. The layer of claim 59, further comprising one or more corrosion resistant pigments.

87. The layer of claim 59, wherein said composition is aqueous-based.

88. The layer of claim 59, wherein said composition is solvent-based.

89. The layer of claim 59, wherein the equivalent ratio of the phosphorous-containing material to epoxy-functional material is between 0.5 and 3.5:

1.