×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

Al2O3 vs TiO2 paint pigment

Al2O3 vs TiO2 paint pigment

Al2O3 vs TiO2 paint pigment

(OP)
Could Al2O3 replace TiO2 as paint pigment if it was economically available in the 300 to 800 nanometer range?  TiO2 is generally coated with Al2O3 because of TiO2 photochemical reactions.  Is TiO2 only used because it is easy to make the particle size range economically?  Since lead, zinc, and other metal oxides have been used in the past it seems that titanium has no intrinsic properties other than its particle size.  I have a way to make spherical sub-micron Al2O3 particles at low cost, so this is an obvious use.

RE: Al2O3 vs TiO2 paint pigment

I've heard it said that TiO2 has better UV reflectance (presumably relative to other oxides) and thus less pigment is required per unit area to achieve good coverage/color.

RE: Al2O3 vs TiO2 paint pigment

I thought TiO2 was "whiter" than alumina

TTFN

RE: Al2O3 vs TiO2 paint pigment

TiO2 has an exceptionally high index of refraction. Thus particles in a transparent liquid or polymer have maximum light scattering effect (hiding power). Particles that have the same index as the liquid they are in become invisible and don't affect transparency. It is whiter than alumina.

RE: Al2O3 vs TiO2 paint pigment


Often times, "pure" white isn't desired in paint.
In fact, many times, white paint bases are knocked off slightly with some "B" or "LB" black colorants in order to increase the "hide" of the coating.  It's basically a cheat that everyone in the industry uses.

The ratio of Ti02 to binder/solvent in a paint is not linear when used to increase hide.  There is a point that adding more Ti02 does nothing more than increase cost.


As far as a Ti02 alternative, if Al2O3 grinds in the same manner as Ti02, performs the same under exposure to UV, is compatable with glycol based colorants, has the same tint strength, doesn't chalk, etc, etc, etc, then it might just have a shot at offsetting Ti02.

Right now demand on Ti02 is so tight, you probably could make a small fortune for yourself developing an offset.



Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources