Claims
- 1. A process for producing a photographic support comprising a substrate, at least one side of which is coated with a thermoplastic resin composition, wherein the process comprises the following steps:
- (a) adding at least one alkaline earth metal compound to titanium dioxide in an amount of 0.01-2.0% by weight in terms of a metal oxide based on the titanium dioxide before calcination, and subjecting the titanium dioxide and alkaline earth metal compound to calcination,
- (b) acid-washing the titanium dioxide at acidic state after the calcination and before a step of surface treatment with a hydrated metal oxide,
- (c) drying the titanium dioxide,
- (d) grinding the titanium dioxide, whereby a particle size of the titanium dioxide is 0.110-0.150 .mu.m shown by number-average diameter obtained by measuring the diameter in a certain direction using an electron microscope,
- (e) kneading the resulting titanium dioxide pigment with a thermoplastic resin to obtain a resin composition, and
- (f) melt-extrusion coating the substrate with the thermoplastic resin composition.
- 2. A process according to claim 1, wherein the thermoplastic resin is a polyolefin resin.
- 3. A process according to claim 1, wherein the thermoplastic resin composition contains an antioxidant.
- 4. A process according to claim 3, wherein the antioxidant is a hindered phenol type antioxidant.
- 5. A process for producing a photographic support comprising a substrate, at least one side of which is coated with a thermoplastic resin composition, wherein the process comprises the following steps:
- (a) adding at least one alkaline earth metal compound to titanium dioxide in an amount of 0.01-2.0% by weight in terms of a metal oxide based on the titanium dioxide before calcination, subjecting the titanium dioxide and alkaline earth metal compound to calcination,
- (b) acid-washing the titanium dioxide at acidic state after the calcination and before a step of surface treatment with a hydrated metal oxide,
- (c) drying the titanium dioxide,
- (d) grinding the titanium dioxide using a fluid energy mill, whereby a particle size of the titanium dioxide is 0.110-0.150 .mu.m shown by number-average diameter obtained by measuring the diameter in a certain direction using an electron microscope,
- (e) kneading the resulting titanium dioxide pigment with a thermoplastic resin to obtain a resin composition, and
- (f) melt-extrusion coating the substrate with the thermoplastic resin composition.
- 6. A process according to claim 5, wherein the polyolefin resin in a polyethylene resin.
Priority Claims (1)
Number |
Date |
Country |
Kind |
2-162084 |
Jun 1990 |
JPX |
|
Parent Case Info
This is a continuation of application Ser. No. 08/094,951, filed on Jul. 22, 1993, which was abandoned upon the filing hereof which is a Divisional of Ser. No. 07/714,847, filed Jun. 13, 1991, now U.S. Pat. No. 5,264,033.
US Referenced Citations (8)
Foreign Referenced Citations (2)
Number |
Date |
Country |
50-364440 |
Nov 1975 |
JPX |
59-1544 |
Jan 1984 |
JPX |
Divisions (1)
|
Number |
Date |
Country |
Parent |
714847 |
Jun 1991 |
|
Continuations (1)
|
Number |
Date |
Country |
Parent |
94951 |
Jul 1993 |
|