Note: Descriptions are shown in the official language in which they were submitted.
RUST INHIBITING COATING COMPOSITIONS
; This invention relates to corrosion resistant or
; rust preventing metal coating compositions useful in inhibiting
- corrosion and rust formation of painted articlesO In
particular it is directed to coating compositions containing
barium salts of organic hydrox~ acids and there hydrates. The
invention is also directed to a method of inhibiting corrosion
in ferrous metals by the appication of a nontoxic lead-free
corrosion resistant barium salt-containing coating to the
surface of the metals.
Presently available corrosion inhibiting compounds,
such as red lead, zinc chromate and lead chromate, act as
anodic inhibitors against corrosion. Heretofore, the
substitution of non-toxic inexpensive fillers and
anti-corrosion pigments for these toxic materials has not been
successful since their use results in a reduction in corrosion
resistance.
It is therefore an object of the present invention
to provide a method for increasing the corrosion inhibition of
metal by applying a novel film-forming composition over its
surface.
Another object provides a novel corrosion
inhibiting composition.
ICI Americas Inc.
Docket 1386
,. ' ~ , ~, '
6~
It is an additional object to provide a pigment
which inhibits corrosion when incorporated in a film-forming
resin binder paint formulation. Pigment blends coprecipitated
on inert substrates are also included.
These and other objects of the invention are
realized by applying to metals paint systems containing an
effective amount about 5-95~ by weight of a barium salt of a
carbonyl group containing organic compound having at least one
acidic hydroxy hydrogen. Representative of such compounds are
substantially water insoluble hydrous and anhydrous barium
salts of organic acids, such as citric acid, tartaric acid,
salicylic acid, alizarine (1,2 dihydroxy-9,10-anthraquinone),
quinizarine (1,4-dihydroxy-9, 10-anthraquinone), chloranilic
acid (2,5-dichloro-3,6 dihydroxyquinone), alizarincarboxylic
acid (5,6 or 7,8)dihydroxy-2-anthraquinone-carboxylic acid and
blends thereof. Surprisingly, such barium salts when
incorporated in films which contact metal surfaces,
particularly iron and steel surfaces, offer a method for
inhibiting corrosion equivalent to or better than most toxic
lead and chro~ium-containing pigments.
Barium salts have been known for some time to be
suitable pigments in the formation of corrosion inhibiting
paints, such as described in U.S. 2,392,102; 2,409,950;
2,479,988; 2,573,878; 3,0Q7,880; 3,598,616; 3j673,229;
3,7~6,694; 3,874,883 to name a few. Hydroxy acids and quinoid
compounds are known to inhibit corrosion, such as described in
U.S. 2,366,074; 3,421,908; 3,585l159 and 3,699,052.
Furthermore, barium salts of organic acids have been shown to
be effective anti-corrosion agents as e~emplified in U.S.
2,285,752; 2,509,786; 3,072,572; 3,137,583 and 3,405,072. In
one insta~ce, U.S. 2,420,127 indicates that an ethylenically
unsaturated 12 hydro~y organic acid (ricinoleic) is useful as a
corrosion inhibitor in the form of an alkaline earth metal salt
when combined in a blown castor oil grease which is applied to
metallic components for storage and shipping.
. _ 3 _
The bar~um sal~s of the present invention differ
from those of the prior art in that they are products of basic
barium compounds, such as barium hydroxide, barium oxide and
barium salts and organic materials having acidic hydroxide
groups in a specific relationship with a carbonyl group. These
organic compounds usually have in the range of 2-40 carbon
atoms, and may be saturated, ethylenically unsaturated and
aromatic. Preferred orqanic acids have a molecular weight in
the range of 73-350~ Carbonyl groups may be present as carboxy
ester, carboxyl~ aldo, keto, and amido. Hydroxyl groups may be
attached to a carbon when said organic compounds is saturated;
in the position when ethylenic unsaturation separates the
hydroxyl-containing carbon from the carbonyl carbon; or in the
~, or position when separated by aromatic unsaturation,
such as exemplified in the following corresponding structures:
o
-C-C-C-OH
-C-C=C-COH
O
-C/C / ~C ~Y
Il I
~--C \ ,~ C ~
. .
-- 4 --
In addition to barium salts of the compounds
mentioned above, barium salts of other materials, such as
glutaric acid, glycolic acid, glyceraldehyde, glyceric acid,
malic acid, gluconic acid, and ~-hydroxy propanoic acid, to
name a few, are additional examples of materials which would be
effective either as anhydrous or hydrated salts of barium as
sole ingredients, blends or deposits on inert or active
substrates.
The corrosion resistant film formulations can be
applied directly to the bare metal or over an adhesion
promoting primer. The preferable choice of application is the
direct coating of a clean grease-free metal sur~ace, however,
many industrial applications require a stronger bond of paint
to metal. This is generally achieved by employing an adhesive
promoting primer which contains the corroslon inhibiting
pigments. However, if acrylic latex or chlorinated rubber type
binder resins are employed, no primer coat is required in
addition to the corrosion inhibitor. The barium salt pigments
are usually employed in coating compositions in amounts ranging
from 5-95 percent by weight, however, smaller amounts in the
order of 0.5 percent by weight are effective in some instances.
The binder resin base for the instant coating
formulations can be any of the air dried oil type, acrylic
resin type, an alkyd resin base, an epoxy resin base, a
polyvinyl acetate base, a latex rubber or chlorinated rubber
base, and any other suitable resin formula normally intended
for use in preparing coatings for metal surfaces. Such
materials are readily available commercially and are well-known
to the art. They may be first applied as a barium salt
containing primer coat for which a top coat is intended.
In addition to the barium salts may be included
pigments, fillers, dyes, colorin~ agents, such as titanium
dioxide, zinc oxide, magnesium silicate, silica, mica, calcium
carbonate, fungicides, algaecides, and compatible thinners
normally employed with the base resin binder chosen.
-- 5 --
The barium salts of the organic materials are
usually formed by adding solutiorls containing basic barium
compounds to solutions containing the above described organic
acidic materials or their soluble salts. The precipitated
barium salt is filtered, washed and dried by conventional
techniques.
Preferred techniques include coprecipitation of
mixtures of carbonyl-hydroxy organic compounds having 2-40
carbon atoms with barium hydroxide. Furthermore, these barium
salts can be precipitated in slurries of active or inert
particulate materials such as clay, silica, alumina, carbon,
glass, inorganic pigments, organic resins and other water
insoluble salts so that the active barium compound is formed on
the surface of the particulate substrate or upon another active
barium salt substrate. Such materials having at least 0~1%
barium by weight can be effective.
Hydrated barium salts of the invention can be
prepared along the lines of the following preparative examples
which lead to the formation of various hydrated barium salts
containing 1-8 molecules of water. Any suitable preparative
method can be used in place thereof and the invention should
not be limited to the barium compounds made according to the
following procedure:
Preparation 1 - Barium Cltrate
Into a glass beaker is intermixed citric acid and
barium hydroxide 8 hydrate (Ba(OH)2.8 H2O) in a mol ratio
of 1/1.5 by intermixing 300 grams of distilled water, 96 grams
citric acid and 236.6 grams of barium hydroxide 8 hydrate
heated to a temperature of 58~C. Upon precipitation of the
barium citrate, 100 grams of distilled water is added whereupon
the white pasty pigment slurry is then held for an additional
hour at 70 90C. A total of ~04.6 grams of a white fluffy
powder is obtained which corresponds to a yield of 92% of
hydrated ~arium citrate. Analysis^ 47.45% Ba. Ba3 C12
14 Hlo
Preparation 2 - Barium Tartrate
Hydrated barium tartrate is prepared by intermixing
315.5 grams barium hydroxide 8 hydrate, 150 grams of tartaric
acid and 400 grams of water with stirring at 50C. Upon
thickening, another 100 grams of distilled water is added and
further heated to about ~0-95C for 1 hour. The slurry is
cooled to 1 and filtered. Filter cake resulting from vacuum
drying overnight at 90-95C was 288 grams of fine powder
Ba2(C4H4o6)2 2 2
Preparation 3 - ~arium Salicylate
Hydrated barium salicylate is prepared by the
intermixing of 157.75 grams of barium hydroxide 8 hydrate,
69.06 grams of salicylic acid and 350 grams of distilled
water. Barium salicylate precipitates as a white slurry upon
heating and stirring for one hour at 75-95C. Upon cooling,
filtering and drying in a vacuum oven at 90-95C overnight a
140.5 grams of hydrated barium salt is obtained.
Ba(C6H4OHco2)2 H2O
Preparation 4 - Barium Alizarate
The barium salt of alizarine (1,2 dihydroxy-9,
10-anthraquinone) is p~epared by intermixing a 2-1 mol ratio of
alizarine and barium hydroxide octahydrate (240~22 grams of
alizarine and 175.75 grams barium hydroxide 8 hydrate) in 600
ml. of water in a 2 1. glass beaker. The mixture turns purple
upon the formation of a pasty mixture. The slurry is stirred
for an additional 2 hours at 90C and filtered at room
temperature, after which the filter cake is dried at 90-95C
overnight in a vacuum oven to yield 237.2 grams of fine
free-flowing powder ~a [C6H4(CO)2 C6H2O2]2
-- 7
Preparation 5 - Barium Quinizarate
The barium salt of quinizarine (1,4-dihydroxy 9,
10-anthraquinone) is prepared by dissolving in 350 grams of
water, 84.5 grams of barium hydroxide 8 hydrate and 115.5 grams
of quinizarine at a temperature of 40C. A dark purple
precipitate forms immediately. The slurry is then stirred at
95C for a period of 1 hour after which it is filtered, washed,
and dried. 151.2 grams of a dark purple free-flowing pigment
is obtained. Analysis 23.9% Ba.
Pr~ ration 6 - Barium Salt_Coated Substrate
As pointed out previously, it may be desirable to
precipitate active corrosion resistant barium compounds on to
inert carriers. A pigment consisting of 60 percent by weight
alumina trihydrate (Alcoa C-331~*, 30 percent by weight barium
citrate and 10 percent by weight barium alizarate is made as
follows: 72.4 grams of barium hydroxide 8 hydrate is dissolved
in 300 ml. of distilled water in a 1 liter beaker at 50C.
Into this is stirred 103 grams of alumina trihydrate. This
slurry is heated to 70C and thereafter 50 grams of an aqueous
solution containing 4.32 grams citric acid and 15 grams of
alizarine are added simultaneously with vigorous stirring. The
color of the slurry turns purple and an increase in viscosity
is noted. Another 200 ml. of ~ater is added and heated to a
temperature of 90-95C and held for 1 hour. The pigment slurry
is then cooled and filtered, washed repeatedly with water, and
dried overnight at 90C. After yrinding the pigment in a
mortar and pestle, 134 grams of a uniformly purple colored
free-flowing pigment is obtained. The pigment can be employed
in corrosion resistant coa~ings as shown in Example 7~
As demonstrated in Preparation 6, similar inert
substances, such as previously described, can be coated with
single or multiple component active barium corrosion inhibiting
salts.
* Reg. TM .
,
,
.,
-- 8 --
Coatl ng Examjples
-
Examples 1 thru 7 of Table II and demonstration
Example ~A) thru (I) of Table I serve to show the improvement
offered by the coating compositions of the invention over those
materials used as anti-corrosive pigments in conventional
commercial formulations and which are considered to be the best
available in industry.
In Tables I and II are indicated the compositions
of the demonstrations examples as well as those of the present
invention when incorporated in rubber base coating formulations
and thereafter subjected to salt spray tests as described in
ASTM B~117-73 for 1,000 hours.
The coating compositions were prepared by mixing 40
parts by weight of pigment indicated with 50 parts by weight of
a chlorinated rubber solution made by mixing 266 parts by
weight Alloprene X-20* (a commercially available chlorinated
rubber); 134 parts by weight Cerechlor 42P* ~a commercially
available chlorinated plasticizer; 400 parts by weight Solvesso
lOO*(a commercially available petroleum solvent); 200 parts by
weight Atlantic 57* (a commercially available petroleum
solvent); 140 parts by weight xylene and 60 parts by weight
Butyl Cellosolve* (a polyoxyalkylated butyl alcohol solvent).
The pigment compositions and chlorinated rubber solutions were
ground together in ball mills for 24 hours usin~ porcelain
pebbles as grinding media. The pigmented coatings were
filtered throu~h a cheese-cloth type paint strainer and
adjusted to a brushable viscosity using small amounts of the
following solvent blend: 200 parts by weight of Atlantic 57;
400 parts by weight of Solvesso 100; 140 parts by weight of
Xylene; and 60 parts by weight of Butyl cellosolve.
Brushed coatings are applied to 7.Scm x 15 cm low
carbon steel p~nels, i~e, two brush coats within 24 hours to
meet requirements of ASTM A-366. All panels are washed with
acetone before painting with two coats of coating composition.
* Reg. TMs
e~
- 9 -
Back, sides and edges of the panels are coated with a red lead
primer and a white alkyd base coating for general protection.
After conditioning the panels at room temperature for two
weeks, the test side coatings are cut diagonally with a razor
blade to the bare metal forming a figure X with the
intersection meeting at the center of the panel on the test
coating side.
The test side was exposed to a salt spray test as
described in ASTM B-117~73. After exposure the test coatings
are removed with the above described solvent blend, dried and
rated as described below. This procedure is used for all test
panels.
The following rating system was adopted to measure
corrosion resistance. The amount of rust was measured in
millimeters along the X-cut at its farthest extension. The
blank areas along side of the X-cut were visibly inspected for
rust spots, discoloration, etc. A final overall rating system
was used to rate the appearance of the test panels.
A - Excellent, no rust along X and no rust on
surface.
B - Good, very little rust along X and no rust on
surface.
C - Fair, moderate rust along X and some rust spots.
D - Poor, heavy rust along X or badly rusted
surface.
The salt spray results are indicated in Tables I
and II. The nine demonstrations (A thru I) indicated that
commercially available pigments are relatively poor as compared
to the pigments of the invention as indicated in Table II. The
barium salts are nearly successful in preventing rust
entirely. It is expected that more rust will occur along the
edge of the panel where coatings are thin~
6~
-- 10 --
Examples 8-12
Tables III and IV identify chlorinated rubber
coatings exposed to a heavy industrial atmosphere at Atlas
Point in Wilmington, Delaware, U.S.A., located at the
waterfront next to the Delaware Memorial Bridges. The coating
compositions were prepared at a 1/1 pigment/binder ratio by
mixing the ingredients in a ball mill for 24 hours using
porcelain pebbles as grinding media. The pigmented coatings
were filtered through a cheese-cloth paint strainer and
adjusted to a brushable viscosity with small amounts of the
solvent blend described in Examples 1-7.
Two sets of coatings are prepared by applying two
brush coats within 24 hours to 7.5cm x 15cm low carbon steel
panels. All panels are washed with acetone before coating with
the anti-corrosive primers made as described above. In
addition to the brush coats one set of panels is topcoated
with a commercially available white alkyd soybean oil-based
paint. The back sides of the panels are coated with a red lead
primer and the white alkyd topcoat for general protection. The
edges are also coated with the white alkyd topcoat. After
conditioning the panels at room temperature, the test side
coatings are cut diagonally with a razor blade to the bare
metal to form an X configuration to intersect in the center of
the panel. They are then exposed at a ~5 angle facing south
at the location cited above. The coatings are washed off with
the previously mentioned solvent and rated according to their
ability to prevent corrosion. They are measured along the X
cut and rated as described in the previous Examples.
Since it is customary to protect primer coats with
one or two topcoats, most emphasis should be given to the set
of panels protected with such a topcoat. On the other hand,
many steel parts are primer coated prior to delivery to the
construction site and are exposed to the atmosphere for many
months before a topcoat can be applied. It is extremely
important that the shop prime~ be corrosion inhibiting.
.
The coatings of these examples are based for
simplicity on the strict pigment/binder weight ratio rather
than on an equal pigment volume concentration. It is
contemplated that optimum formulations can be developed by
inclusion of antisettling agents, pigment wetting aids, and
additives to prevent flash rusting. While Table III indicates
that a few conventional primer coatings are satisfactory after
one year outdoor exposure when topcoated, they are no match for
the barium pigments listed in Table IV. These pigments indicate
practically no rust when exposed under similar conditions.
While barium chloranilate (a commercially available reaction
product of barium hydroxide with 2,5-dichloro-3,6-dihydroxy-
quinone, also referred to as chloranilic acid) is used incombination with barium salicylate, it can be used alone or in
combination with other barium salts.
Exam~es 13 - 22
Coating compositions prepared as described above
containing 60 parts of the Alloprene* chlorinated rubber
solution described in Examples 1-7 of Table II and coated on
steel panels as described in previous examples are exposed as
are the test panels of Examples 8-12 of Table IV for a period
of 1 year. The concentrations of the conventional pigments and
the barium salts are diluted about 50~ using calcium carbonate
pigment, commercially available from Thompson, Weinman Co. as
Sno Flake.
The xust rating tests indicate that the barium
salts and combinations thereof inhibit rust to greater degree
than those of the conventional pigment demonstration Q, R, S,
and T of Table V.
Examples 23 - 26
To demonstrate the effect of the experimental
pigment using a water-based emulsion acrylic copolymer "Rhoplex
MV-2"*, a product of Rohm ~ Haas Corp., a series of coatings
using 80 parts Rhoplex with 36 parts of the primer pigment, the
* Reg. TMs
. ~
~,2~.~
6~
- 12 -
compositions of which are shown in Tables VII and VIII are
ground in a ball mill at a 1/1 pigment binder ratio using the
ball mills previously described. One set of the panels is
prepared using two primer brush coats. The second set of
panels, in addition to the two primer coats, is coated with one
brush coat of white commercial soybean oil based alkyd paint.
After conditioning the panels at room temperature for 3 weeks,
they are cut diagonally and exposed on a test fence in a heavy
industrial atmosphere, as described in Examples 8-22 of Tables
IV and VI. After two years exposure they are removed and rust
tested as previously described. In Tables VII and VIII is
shown the compositions of the invention have practically no
rust.
--13--
TADLE I
1000 HR. SALT SPRAY CORROSION - CONVENTION~L PIGMENT PRI.~E'
Pigment Primer tParts Picment with 60 Part5 Chlorinat~d ~hh^r
Demon~trations A E C D E P G H
Red Lead(Pb3o~) 20
Calcium CarbonQte 2020 20 20 2040 20 20 2
Modi~ied 5arium Metaborate 20
Zinc Phosphats #317 20
Cnlciumrbarium Phosphosil1cate 20
Calclum-strontium Phosphosilicate 20
Zinc Chromnte 20
5aslc Leed Slllco Chromate 20
Zinc 0a~ed Pigment 20
~ST TEST RUST RAT~NG RESULTS
~m of Rust a~ong X Scratch~ 1^2 2-5 8 0 0 3-5 0 1-3 i-~
Rust on Surface~ ~-C C D D D C D D D
~Code: 5 - Edge attack
C - Rust 5pO~5 ~ edge attack
D ~0~ oe gr-:eer ~ ~t coV red
,~
'.'~
. .
'
!
-
TABLE II
1000 IIR. SALT SPRAY CORROSION - EXAMPLES 1-7 PRIMERS
Primer Compound ~Parts Pigment with 60 Parts Chlorinated RU~
Examples 1 2 3 4 5 6 7
Barium Alizarate Prep. 4 6 2 6 3 3
Barium Citrate Prep. 1 3
Barium Tartrate Prep. 2 3
~ar$um Quinizarate Prep. 5 20
~ixed pigment on inert carrier-
Prep 6 (60~ Aluminum Trihydrate,
30~ Barium Citrate Prep. 1, 10g
Barium Alizarate Prep. 4) 20
Red Lead 14 8
Calcium Carbonate 20 30 34 34 34 20 20
RUST TEST RUST RATING~
mm of Rust along X Scratch 0-2 0-2 D-3 0-2 1-2 1-3 0-3
Rust on Surface~ A-B A-B A-~ A-~ A-B A-B
*Code: A - No rust
B - Edge Attack
_ . . . . `:
. ~
.
15~
TABLE III
1 YR~ OUTDOO~ EXPOSURE - CONVENTIONAL PIGMENTS PRIMER
Pigment Prlmerb (Parts Piqment w 60 Pts. Chlor~r_ated Rubber Solution)
Red Lead 40
Calcium Carbonate 40
**
Molywhite l01(Lead free Primer) 40
Phosphated Zinc Oxide 40
Boron-Silicate Pigment
Zinc Chromate 40
Basic Lead Silico Chromate 40
RUST TESTRUST RATING ~PRIMER COAT)
mm of Rust along X Scratch 8-10 3-5 5-20 1-8 1-2 3-6 1-4
Rust on Surface*C D D C B C B
(PRIMER & TOP COAT)
mm of Rust along X Scratch 3-5 1-3 5-20 1-2 1 2 1-2 1-3
Xust on Surface* C B-C D B A-B B-C B-C
*Code: A = No rust
B = Edge attack
C = Rust spots + edge attack
D = 50% or greater rust covered
** Reg. TM
', ,
-16- ~ ~Z 6 oa3 8
TAB1E IV
.
1 YR. OUTDOOR EXPOSURE - EX~PLES 8-12 PRIMER
Pigment Primer (Parts Pigment w 60 Pts. Chlorinated Rubber Solution)
Examples _ 9 ~ I2 - ~
Barium Citrate Prep. 1 40 34
Barium Alizarate Prep. 4 6 40
Barium Salicylate Prep. 3 40 34
Barium Chloranilate (Commer. avail) 6
RUST TEST RUST ATING~PRIMER COAT)
mm of Rust along X Scratch 1 0 1 1 0
Rust on Sur~ace* A-B A D D A
(PRIMER & TOP COAT)
mm of Rust along X Scratch 1 0 0 0 0
Rust on Surface~ A-B A A-B A A
*Code: A = No rust
B = Edge attack
C = Rust spots + edge attack
D = 50~ or greater rust covered
~` '
-17-
6~8
TABLE V
l-YEAR OUTDOOR EXPOSURE
CO~ ENrl~AL PrZRil~ PRIMER
WITH CALCIUM CARBONATE
, , ~Parts w 60 Pts. Chlorinated Rubber Solution)
Pl~ment Prlmer ' -~~~
Demonstrations Q R S T
Red Lead 20
Calcium Carbonate 20 20 20 40
Buson ll-M-l* 20
Zinc Phosphate 20
RUST TESTS . UST RAT.ING*~PRIMER COAT)
mm of Rust along X Scratch 8-10 1-2 1-2 1-2
Rust on Surface* D D D D
~PRIMER + TOP COAT)
mm of Rust along X Scratch 1-3 1-3 1 1-3
Rust on Surface* C C B C
*Codes: A = No rust
B = Edge attack
C = Rust spots + edge attack
D = 50% or greater rust covered
** Reg. TM
' .
.' ~ '
:,, .
~6`~
,~,
ABLE VI
1 YEAR OUT W OR EXPOSUR - EXAMPLES 13-22 WITH CALCIUM CARBONATE
Pi~ment Prim~er
Examples13 14 15 16 17 10 19 20 21 22
Barium Alizarate Prep. 4 6 6 20 6 6 6
8arium Citrate Prep. 1 20 20 20 20 20
8arium Ouinizarate Prep. S 6-
Barium Salicylate Prep. 3 20
Bartum Tartrate Prep. 2 20
Alizarlne 6
Benzoquinone 6
Calcium carbonate 34 2014 14 14 14 20 14 14 14
Red Lead 20
RUST TEST RUST P~ATING~IPRIMER COAT)
mm of Ruse along X Scratch 3-5 1 0 1 0 0 0 2 3-5 3-5
Rust on Surface D D A A A A A C C C-D
IPRIMER ~ TOP COAT)
mm of Rust along X Scratch 1-3 1 1 1 i 1 0 1-2 1 1-3
Rust o~ Surface~ C 8 A-8 A-B A-UA-B A 8 B C
sCode: A 8 No rust
8 ~ Edye Attack
C Y Rust spots ~ edge uttack
D 8 50~ or greater rust covered
~}
.
.
TABLE VII
2-YR. OUTDOOR EXPOSURE - CONVENTIONAL PIGMENTS PRIMER
.
Pigment Primer (Parts w 80 Pts. AcryI;c CopolYmer)
Demonstrations U V W X Y
Red Lead 36
Molywhite 212 36
Zinc Phosphate Complex 36
Borosilicate Pigment 36
Calcium Carbonate 36
RUST TESTS RUST RATINC*(PRIMER COAT)
.
mm Rust along X scratch1-3 1-3 2~5 2-5 1-3
Rust on Surface* C C C C C
(PRIMER & TOP COAT)
mm Rust along X Scratch2-4 1-6 1 1-2 1-3
Rust on Surface* B-C B A-B C C
*Code: A = No rust
B = Edge attack
C = Rust spots + edge attack
D = 50% or greater rust covered
** Reg. TM
;1` a
-20-
TABLE VIII
2-YEAR OUTDOOR EXPOSURE - EXAMPLES 23-26
Pi~ment Primer
Examples _ 24 25 26
Barium Citrate Prep. 136 30
Barium Chloranilate 6
Barium Alizarate Prep. 4 36 6
Barium Tartrate Prep. 2 30
.
RUST TEST5 RUST RATIN~ (PRIMER COAT)
_.
mm of Rust alon~ X ScratchO O 0-1 p
Rust on Surface* BA-B A-B A
~PRIMER & TOP COAT)
mm of Rust along X ScratchO 0 0-1 0
i Rust on Surface* BA-B A-B A
*Code: A = No rust
B = Edge attack
C = Rust spots ~ edge attack
D = 50% or greater rust covered
'
~ '
"~,..~
;
;'
