Steel plate bonding process and primer composition

• US 3,936,342 A
• Filed: 02/14/1974
• Issued: 02/03/1976
• Est. Priority Date: 02/15/1973
• Status: Expired due to Term

• Current Assignee: Toagosei Chemical Industry Company Limited (Toagosei Company Limited)
• Original Assignee: Toagosei Chemical Industry Company Limited (Toagosei Company Limited)
• Inventors: Matsubara, Takashi, Takeuchi, Yuko, Hirose, Toshiro
• Primary Examiner(s): Drummond, Douglas J.
• Assistant Examiner(s): Ball, Michael W.
• Application Number:
  US05/442,557
• Time in Patent Office: 719 Days
• Field of Search: 156/330, 156/335, 161/186, 161/215, 161/227, 260/831, 260/837, 428/416, 428/460, 428/474, 428/457
• US Class Current: 156/330
• CPC Class Codes: B32B 15/088 comprising polyamides
• CPC Class Codes: B32B 15/18 comprising iron or steel B32B15/011, B32B15/012 and B32B15/013 take precedence
• CPC Class Codes: B32B 2305/72 Cured, e.g. vulcanised, cross-linked
• CPC Class Codes: B32B 27/34 comprising polyamides
• CPC Class Codes: C08G 8/24 with mixtures of two or more phenols which are not covered by only one of the groups C08G8/10 - C08G8/20
• CPC Class Codes: C08L 2666/22 Macromolecular compounds not provided for in C08L2666/16 - C08L2666/20
• CPC Class Codes: C09D 161/06 of aldehydes with phenols
• CPC Class Codes: Y10T 428/31522 Next to metal
• CPC Class Codes: Y10T 428/31678 Of metal
• CPC Class Codes: Y10T 428/31688 Next to aldehyde or ketone condensation product
• CPC Class Codes: Y10T 428/31739 Nylon type

Abstract

A process for bonding steel sheets, e.g., into metallic cans, which comprises applying first a primer comprising 0.1 to 2.5 weight parts of a bisphenol type A epoxy resin having a mean molecular weight of more than about 800, preferably 2000 to 4000, and 1 weight part of thermosetting phenolic resin, which is obtained by heating an aqueous solution comprising phenol, orthocresol and formaldehyde in the presence of a catalyst and reacting them with each other under refluxing conditions, on the surface of the steel sheets, heating the resultant steel sheets, and then bonding the steel sheets with a polyamide, and a primer composition for use in the process.

Claims

1. A process for bonding steel sheets which comprises applying a primer composition comprising 0.1 to 2.5 weight parts of a bisphenol type A epoxy resin having a mean molecular weight greater than about 800 per 1 weight part of a thermosetting phenolic resin obtained by reacting an aqueous solution of a mixture of orthocresol and phenol in a weight ratio of orthocresol to phenol ranging from about 60 :

40 to 10 ;

90 with formaldehyde in the presence of an alkali catalyst, to the surface of the steel sheets, curing the applied primer composition on the steel sheet surfaces, and then bonding said steel sheets with a polyamide.

2. The process according to claim 1, wherein said steel sheets are chromated steel sheets.

3. The process according to claim 1, wherein said steel sheets are zinc plated steel sheets.

4. The process according to claim 1, wherein said steel sheets are untreated rolled steel sheets.

5. The process according to claim 1, wherein said bisphenol type A epoxy resin has a mean molecular weight of 2000 to 4000.

6. The process according to claim 1, wherein the weight ratio of orthocresol to phenol in said thermosetting phenolic resin ranges from 50 :

50 to 15 ;

85.

7. The process according to claim 1, wherein said applying is conducted for less than 5 minutes at a temperature of higher than 210°

C.

8. The process according to claim 7, wherein said polyamide is selected from the group consisting of nylon 11, nylon 12, nylon 13, nylon 610, nylon 612, nylon 613, nylon 612/12 and nylon 12/6.