Claims
- 1. A chromated metal sheet that has high corrosion resistance along with improved lubricity and electrical conductivity, comprising: a chromate layer on at least one surface of a metal substrate or a plated metal substrate,
- wherein said chromate layer has a chromium deposit in the range of 10-200 mg/m.sup.2 per surface in terms of metallic Cr,
- wherein said chromate layer contains silica in a weight ratio of 0.1-6.0 of SiO.sub.2 to Cr and lubricating particles selected from the group consisting of graphite, MoS.sub.2, BN, calcium stearate and an organic lubricating substance, said lubricating particles being present in a weight ratio of 0.1-100 of the lubricating particles to Cr, and wherein the coverage of the surface of said metal substrate with said lubricating particles is less than 50%.
- 2. A chromated metal sheet according to claim 1 wherein the organic lubricating substance comprises particles selected from the group consisting of natural waxes, polyolefin waxes, modified polyolefin waxes and fluorocarbons.
- 3. A chromated metal sheet according to either of claims 1 or 2 wherein said metal substrate is a steel sheet.
- 4. A chromated metal sheet according to either of claims 1 or 2 wherein said plated metal substrate is an electrogalvanized steel sheet or a hot-dip galvanized steel sheet.
- 5. A chromate metal sheet according to claim 1, wherein said lubricating particles have an average particle size of less than 20 .mu.m.
- 6. A chromate metal sheet according to claim 1, wherein said improved electrical conductivity is equivalent to surface electric resistivities of less than 0.5.OMEGA..
- 7. A chromate metal sheet according to claim 1, wherein said chromate metal sheet is capable of withstanding press forming in the absence of lube oil coating.
- 8. A chromate metal sheet according to claim 1, wherein said chromate metal sheet is capable of being used for parts for home electrical appliances.
- 9. A chromate metal sheet according to claim 1, wherein said lubricating particles have a surface layer capable of nonionic surface activating action formed on the lubricating particle, said surface layer capable of nonionic surface activating action being about 1%-70% by weight of said lubricating particle, said lubricating particles as calculated in terms of the lubricating particle being present in a weight ratio of 0.1-100 to Cr.
- 10. A chromated metal sheet possessing the combined properties of high corrosion resistance, improved lubricity and improved electrical conductivity, comprising:
- a metal substrate,
- a chromate layer adhered to said metal substrate,
- said chromate layer comprising a chromium deposit in the range of 10-200 mg/m.sup.2 expressed as metallic Cr,
- a plurality of silica particles dispersed throughout said chromate layer in a weight ratio of 0.1-6.0 parts by weight of SiO.sub.2 per unit weight of Cr;
- a plurality of lubricating particles dispersed throughout said chromate layer, said lubricating particles being selected from the group consisting of graphite, MoS.sub.2, BN, calcium stearate and an organic lubricating substance, said lubricating particles being present in a weight ratio of 0.1-100 per unit weight of Cr,
- wherein said lubricating particles are dispersed on the surface of said metal substrate with a coverage of less than 50%; and
- wherein said lubricating particles have a surface layer nonionic surfactant positioned on each of said lubricating particles, said surfactant having nonionic surface activating action and being present in an amount of about 1%-70% by weight of the weight of said lubricating particles, said lubricating particles being present in a weight ratio of 0.1-100 to the weight of Cr.
- 11. The chromated metal sheet defined in claim 10, wherein the said chromium in said chromate layer is predominately trivalent chromium, and
- wherein at least 70 wt % of the total Cr content of said chromate layer is insoluble in an aqueous alkaline solution.
- 12. A chromated metal sheet according to claim 10, wherein the organic lubricating substance comprises lubricating particles selected from the group consisting of natural waxes, polyolefin waxes, modified polyolefin waxes and fluorocarbons.
- 13. A chromated metal sheet according to claim 10, wherein said metal substrate is a steel sheet.
- 14. A chromated metal sheet according to claim 10, wherein said metal substrate is plated and selected from the group consisting of an electrogalvanized steel sheet and a hot-dip galvanized steel sheet.
- 15. A chromated metal sheet according to claim 10, wherein said metal substrate is plated and selected from the group consisting of an aluminum plated steel sheet and an aluminum alloy plated steel sheet.
- 16. A chromated metal sheet according to claim 10, wherein said metal substrate is selected from the group consisting of an aluminum sheet and an aluminum alloy sheet.
Priority Claims (1)
Number |
Date |
Country |
Kind |
5-187924 |
Jul 1993 |
JPX |
|
Parent Case Info
This application is a continuation of now abandoned application Ser. No. 08/183,514, filed Jan. 18, 1994.
US Referenced Citations (5)
Number |
Name |
Date |
Kind |
2809127 |
Gibson et al. |
Oct 1957 |
|
4411964 |
Hara et al. |
Oct 1983 |
|
4799959 |
Fourez et al. |
Jan 1989 |
|
4804587 |
Takeuchi et al. |
Feb 1989 |
|
5389436 |
Totsuka et al. |
Feb 1995 |
|
Foreign Referenced Citations (10)
Number |
Date |
Country |
0 150 650 |
Aug 1985 |
EPX |
54-161549 |
Dec 1979 |
JPX |
60-103185 |
Jun 1985 |
JPX |
61-227178 |
Oct 1986 |
JPX |
61-279687 |
Dec 1986 |
JPX |
63-83172 |
Apr 1988 |
JPX |
1-110140 |
Apr 1989 |
JPX |
2-034792 |
Feb 1990 |
JPX |
61227179 |
Oct 1996 |
JPX |
1 421 261 |
Jan 1976 |
GBX |
Continuations (1)
|
Number |
Date |
Country |
Parent |
183514 |
Jan 1994 |
|