Document 9J32oE20QkgmLNEXrGZa0OMn5
ALLIED RESEARCH BULLETIN RC-58
SUBJECT: ACICTJLAR ZINC OXIDE AND ACICULAR LEAD SULPHATE -
BEHAVIOR IN TINTED PAINTS.
C. H. Adams
May 23, 1940.
ALLIED RESEARCH LABORATORIES CHICAGO, ILLINOIS
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Acicular Zinc Oxide and Acicular Lead Sulphate Behavior in Tinted Faints
Statement Ihe Pittsburgh Plate Glass paint technologists claimed superior
Acicular Zinc Oxide and Basic Lead Sulphate as against a co-fumed Leaded Zinc in their light colored house paints.
Information was received from another source to the effect that they also were using an Acicular Basic Lead Sulphate.
In evaluating their claims as to the superior performance of Acioular Zinc Oxide, both the standard and the Acicular Basic Lead Sulphates
re used. Also, tho Anaconda Acicular Zinc Oxido, as well ns the American
The Pittsburgh Plato Glass pigment formula is approximately as follows:
35/S Basio Load Carbonato 54# ^Leaded Zinc, or equivalent (35# Zinc Oxide, 19# Load Sulphate) 11# Inert Pigmont
TO
*In exposure Ho. 3 whero Oslo 50/50 was used, this Loaded Zinc reprosontod 70# of tho total pigmont.
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Tho paints rraro shaded to a conventional Croam and Gray color, ppliod three coats solf-primcd on White Pino. Exposed vortioally at qjjlcago tost farm. Exposuro period 16 months.
It is to bo noted that tho Zinc Oxido content of 35$ is somewhat gher than generally used in Outside Vihito Paints, and about in tho middle *snge of tho majority of light colored paints.
. .
osuro Results
While this sorios of exposures has not progressed to the point-of inal evaluation, tho failures which have occurrod are sufficiently dofinito Eto indicate what can bo oxpooted.
The tinting colors used in producing tho tints aid somewhat in
creasing durability as against the some formulation in tho Whito.
?
Leaded Zinc
or Equivalent
Chocking
Gray
Croam
Color Retention
Gray
Crecm
Oslo 35/65
Afco Co*-i\aiiGd Oslo 50/50 Std. Basic Lend Sulphate* and XX Zinc Oxido** Aoioular Basie Load Sulphate and XX Zinc Oxide Std, Basic Lead Sulphate and ir- ' Am, Aoicular Zinc Oxido Std. Barfic Load Sulphate and Anaconda Aoicular Zino Oxido Acicular Basic Load Sulphato and Am. Acicular Zinc Oxide
Absent Absent.
to Slight.
nm
it
Absent.
"
Bad Bad
if n
Absent Absent
Vory Slight. "
n t
it
Badly faded.
If
Tt
Sadly fadedi
M
tt
11 tl
If fl
II It
If tt
It it
+ Rational Load Co. ** Now Jorsoy Zinc XX
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Based on the results to date, tho durability performance of Ozlo lso/50 is slightly superior to Ozlo 35/S5, but with an appreciably groator Tdcgreo of fading, definitely tho poorest of the series.-
Tho durability of a mechanical mixture of rogular Basic Lead i'Sulphcte and regular Zinc Oxide is definitely inferior to that of a co-fumod ^Leaded Zino, a consistent exposure result.
Tho introduction of Acicular Zinc Oxide increased durability to degree equal or superior to that of a co-fumod Leadod Zinc,
Tho introduction of Acicular Basic Load Sulphate decreases durability. Tho paints containing American Process Non-Aoicular Zinc Oxide f-shew slight but not considerably tho best color retention, the color retenItion being poor in all instances. In tho Pittsburgh Plate Glass typo of formulation, the substitution f'of a mochnnioal mix for a co-fumod Leaded Zinc has shown no distinctive Superiority to date;
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