Rhoplex AC-3001 - The Dow Chemical Company

12 Pages·2008·0.18 MB·English

RHOPLEX™ AC-3001 EMULSION
Aqueous Acrylic Vehicle for Coatings Over Cementitious Substrates
Description
RHOPLEX AC-3001 emulsion is a thermoplastic all-acrylic binder designed to be formulated into water resistant
finishes with an excellent balance of early block resistance and coalescent demand. Typical applications for factory
applied coatings based on RHOPLEX AC-3001 cementitious substrates include flat and corrugated fibercement tiles
for facade and roofing, and other concrete elements.
RHOPLEX AC-3001 emulsion can be formulated in pigmented coatings as well as clears for application directly to
uncoated or over prepainted cementitious surfaces. As with all aqueous binders, RHOPLEX AC-3001 should be
carefully formulated to meet the various requirements of different substrates and application line conditions.
Performance Features
Coatings formulated with RHOPLEX AC-3001 emulsion offer the following features:
(cid:1) Excellent water-whitening resistance
(cid:1) Excellent water resistance
(cid:1) Early block resistance
(cid:1) Low coalescent demand
(cid:1) Good exterior durability
(cid:1) Low water vapor permeability
Typical Properties
These properties are typical but do not constitute specifications.
Appearance Milky white liquid
Solids content, % by weight 48
pH 7.7 to 8.7
Brookfield viscosity, cP 200 to 500
Density, lbs/US gal 8.8
Dry bulking value, gal/lb 0.1072
Minimum film-forming temperature (MFFT), °C 27
Glass transition temperature (Tg), °C 32
Tukon hardness, KHN 3-5
Typical Performance
The following characteristics of coatings based on RHOPLEX AC-3001 acrylic emulsion have been recommended in
our laboratories and at our exposure stations located around the world. These coatings were compared to coatings
based on PRIMAL™ E-357 emulsion, a similar widely used acrylic vehicle.
Figure 1
Clear Film Water Whitening
RHOPLEX AC-3001 VS PRIMAL E-357
Water-Whitening Resistance
Clear films of RHOPLEX AC-3001 emulsion display excellent resistance to water-whitening in comparison to
PRIMAL E-357 finishes, another widely used vehicle for cementitious coatings, as demonstrated in Figure 1. Not
only do clear films based on RHOPLEX AC-3001 show a minimal amount of whitening under both ambient (25°C)
and elevated (45°C) water soak temperatures, but they also completely recover to visually clear films when
removed from the water.
¹CIE Lab L* Scale: 0 (black) to 100 (white)
(cid:1) Each coalesced [15% EB (BOP)] clear latex was drawn down (5 mil opening) on several preweighed 3" x 4"
black Leneta panels, which were then air-dried for several minutes, and placed in a constant temperature
room (CTR) for 24 hours.
(cid:1) Each sample was dried at 60°C for 64 hours, and placed in a CTR for 24 more hours.
(cid:1) The samples were weighed, initial L* values were recorded, and clear film water-whitening tests were then
initiated by placing the test samples in ambient temperature (25°C) or 45°C DI water.
(cid:1) Measurements for L* were taken at the indicated time intervals, and DL* values (measured L* value minus
initial value) were calculated.
Figure 2
Water Resistance of Clear Films
RHOPLEX AC-3001 VS PRIMAL E-357
Water Resistance
In addition to its other features RHOPLEX AC-3001 emulsion provides excellent early water resistance properties
(see Figure 2). As shown, RHOPLEX AC-3001 compares favorably to the much harder and very water resistant
PRIMAL E-357 polymer.
(cid:1) The same steps in sample preparation were taken as in steps 1 and 2 noted under Figure 1.
(cid:1) The samples were then weighed at the same time intervals used in measuring L* values.
(cid:1) The percent water absorbed (clear film water pickup) by the clear film was then calculated as: [(polymer
wgt at time t initial polymer wgt)/initial polymer wgt] x 100%
Block Resistance
Formulated paints based on RHOPLEX AC-3001 emulsion possess an exceptionally high degree of early block
resistance. Results clearly show the superior block and print resistance of an 18 PVC coating based on RHOPLEX
AC-3001 emulsion compared to one based on PRIMAL E-357, which has a much higher Tg. (Table 1) Paints based
on RHOPLEX AC-3001 demonstrate much higher block and print resistance when formulated to an equivalent
MFFT, which in this case was 28°C. Formulation to other equivalent MFFTs would also be expected to yield similar
results. Thus, a higher level of block resistance can be achieved while lowering the VOC content of the formulation.
Table 1
BLOCK AND PRINT RESISTANCE OF 18 PVC BLACK PAINTS BASED ON
RHOPLEX AC-3001 AND PRIMAL E-357
% Block Print
Binder Tg, °C Coalescent* Resistance** Resistance**
RHOPLEX AC-3001 32 0 9 7
PRIMAL E-357 55 9 4 3
* Coalescent: Ethylene glycol monobutyl ether, % BOP required for 28°C MFFT.
**Rating: 1 - 10 (10 best)
Substrate: Fiber cement
Conditions: 70°C preheat
Face to face block test: 6 hrs/28 psi/50°C platens.
Print test: Cheesecloth between samples, 6 hrs/28 psi/50°C.
Low Coalescent Demand
RHOPLEX AC-3001 emulsion has a much lower Tg than PRIMAL E-357, and in effect requires less coalescent to
reach a given MFFT (or level of paint film integrity). This is illustrated graphically in Figure 3 where the MFFT of
RHOPLEX AC-3001 is plotted as a function of coalescent type and level for a variety of common waterborne
industrial coating solvents. Figure 3 can also be used to determine the amount of a particular coalescent required
to achieve some predetermined target MFFT.
Figure 3
Coalescent Demand of Clear Films
RHOPLEX AC-3001 VS PRIMAL E-357
Exterior Durability
Coatings based on RHOPLEX AC-3001 acrylic emulsion provide comparable durability to those based on PRIMAL
E-357 in a variety of formulations (Tables 2-4). Black, brown and green paints at various pigment volume
concentrations (PVC), based on RHOPLEX AC-3001, applied to preheated fiber-cement panels, at various pigment
volume concentrations, compare favorably to PRIMAL E-357 in both accelerated weathering and standard outdoor
exposures.
Table 2
EXTERIOR DURABILITY OF 18 PVC BLACK PAINTS BASED ON
RHOPLEX AC-3001 AND PRIMAL E-357
% Efflorescence
Vehicle Coalescent* Appearance** Resistance** Face Cracking**
Spring House, PA
RHOPLEX AC-3001 0 10 10 10
PRIMAL E-357 9 9 10 9
Florida
RHOPLEX AC-3001 0 10 10 10
PRIMAL E-357 9 9 10 7
* Coalesced to 28°C MFFT with ethylene glycol monobutyl ether (% BOP).
**Rating: 1 - 10 (10 best)
Exposure Locations: Spring House, PA and Florida, Inland
Exposure Direction: South 45°
Exposure Time: 1 year
Spray-applied to 90°C fiber-cement (1.2 mils) and dried 3 minutes at 90°C.

Table 3
ACCELERATED EXPOSURE RESULTS OF RHOPLEX AC-3001 VS PRIMAL E-357
IN 15 PVC, 25 PVC, AND 35 PVC BROWN PAINTS
Accelerated Exposure Condition and Time: QUV ('A') 1000 hr/QUV ('A') 2000 hr
% Gloss Retention
Efflorence Face Color Fade
Vehicle PVC 60º 85º
Resistance* Cracking* DE**
RHOPLEX AC-3001 15 10/10 10/10 0.2/2.7 100/86 98/94
PRIMAL E-357 15 10/10 6/5 0.7/0.6 86/81 98/65
RHOPLEX AC-3001 25 10/10 10/10 0.7/1.4 100/96 96/86
PRIMAL E-357 25 10/10 9/9 0.5/1.0 100/96 96/86
RHOPLEX AC-3001 35 10/10 10/10 1.0/1.3 100/97 86/68
PRIMAL E-357 35 10/10 10/10 0.8/1.2 100/92 93/81
* Rating: 1 - 10 (10 best)
**Color fade: D E Hunter Units

Table 4
ACCELERATED EXPOSURE RESULTS OF RHOPLEX AC-3001 VS PRIMAL E-357
IN 20 PVC GREEN PAINTS
Accelerated Exposure Condition and Time: QUV ('A') 1000 hr/QUV ('A') 2000 hr
% Gloss Retention
Efflorence Face Color Fade
Vehicle PVC 60º 85º
Resistance* Cracking* DE**
RHOPLEX AC-3001 20 10/10 10/10 0.3/0.5 100/100 100/100
PRIMAL E-357 20 10/10 8/8 0.3/0.3 100/100 95/95
* Rating: 1 - 10 (10 best)
** Color fade: D E Hunter Units
Water Vapor Permeability
Coatings based on RHOPLEX AC-3001 emulsion help to protect the substrate from moisture because of the low
water vapor permeability of RHOPLEX AC-3001 (see Table 5). This is an important factor to consider in the design
of coatings for concrete substrates, where the existence of water and water vapor play a role in the efflorescence
resistance of the finished product.
Table 5
Moisture Vapor Transmission of Clear Films Based on
RHOPLEX AC-3001 VS PRIMAL E-357
Perm Units*
Latex
(grains/ft2/hr/in Hg)
RHOPLEX AC-3001 4.4
PRIMAL E-357 14.2
*Per ASTM D1653-91a
(cid:1) A formulation containing latex and coalescent [15% EB (BOP)] was drawn down (3 mils dry) on Teflon-
coated release paper and allowed to dry for 24 hours in a CTR.
(cid:1) The clear films were dried at 60°C for 48 hours, peeled from the Teflon, and placed in a CTR for 24 hours.
(cid:1) A circular test specimen of each clear film sample was placed over the circular opening of a Perm cup (10
cm²) filled with distilled water.
(cid:1) The weight loss of water was measured every 24 hours until a constant weight change per unit time was
observed.
(cid:1) Perm values were calculated as grains of water lost per square foot of coating surface, per hour, per inch of
Mercury pressure difference between the two sides of the coating.
Formulation Guidelines
Pigmentation
With RHOPLEX AC-3001 emulsion, as in all coating systems, the pigment loading and choice of pigments has a
strong influence on final exterior durability. For best results, we recommend that maximum pigment volume
concentrations (PVC) should not exceed 30%.

We also recommend the selection of highly durable pigments, such as Ti-Pure™ R960, for weatherable exterior
coatings. To maximize durability, the minimum amount of TiO levels necessary for good hiding should be used.
2
Although many kinds of extenders can be used, we recommend the use of mica generally due to the better acid,
chemical, and water resistance that it imparts.
Coalescent
Since RHOPLEX AC-3001 emulsion is not a film former at room temperature, coalescing agents may be required to
achieve optimal film properties, depending on substrate preheating and postheating conditions. Inadequately
coalesced paint films may have fundamental flaws such as cracks, and will result in less than optimal performance.
The choice and amount of coalescent will also have a strong influence on such properties as film formation, and
block, print, water, and efflorescence resistance. In general, 10% ethylene glycol monobutyl ether (BOP) is
sufficient to achieve a satisfactory level of performance. Other satisfactory coalescents include Dowanol™ PnB and
DPnB.
Additives
TAMOL™ 731 is the preferred dispersant for formulating pigmented coatings based on RHOPLEX AC-3001
emulsion. This product provides an excellent combination of dispersing properties with a low level of water
sensitivity. The use of Triton™ CF-10 can also be employed with TAMOL 731 to enhance the wetting of difficult-to-
disperse pigments.
Adequate antifoaming properties can be accomplished with a variety of commercially available defoamers.
Formulations in this brochure included Nopco™ NXZ, Bubble Breaker™ 3056A, Drew™ L108, and Surfynol™ 104E
and 104H.
Typical Starting Point Formulations
The following starting point formulations demonstrate the use of RHOPLEX AC-3001 emulsion in several different
types of finishes including clear sealers, basecoats, and topcoats.
STARTING POINT CLEAR SEALER
FORMULATION BASED ON
RHOPLEX AC-3001 EMULSION
Materials Pounds
RHOPLEX AC-3001 (47.9%) 95.21
Drew L-108 0.11
Butyl Cellosolve™ 4.55
Surfynol 104E 0.13
Total 100.00
Adjust viscosity as needed with water and/or ACRYSOL™ RM-825

FORMULATION BC-3001-W1
STARTING POINT 20 PVC WHITE BASECOAT FORMULATION
BASED ON RHOPLEX AC-3001 EMULSION
Materials Pounds Gallons
Cowles Grind
Water 68.2 8.19
QP™-4400 (2.0%) 53.4 6.36
TAMOL 731 (25%) 6.2 0.67
Triton CF-10 1.6 0.18
Bubble Breaker 3056A 4.2 0.57
Ti-Pure™ R-960 246.4 7.63
Letdown
RHOPLEX AC-3001 (48%) 604.7 68.87
Ethylene glycol monobutyl ether (80%)* 54.4 7.14
Surfynol 104E 3.2 0.39
Totals 1042.3 100.00
Formulation Constants
PVC, % 20
Volume solids, % 38.8
Weight solids, % 51.9
pH, Adjust with NH OH (14%) to: approx. 9.0
4
Viscosity, #4 Ford cup, seconds 20
Coalescent* on binder, % (BOP) 15
VOC, g/L 119.8
VOC, lb/gal 1.0
Note, this level of coalescent is recommended for ambient drying conditions. Elevated
preheat or postheat temperatures would diminish or possibly eliminate the need for
coalescent.
FORMULATION TC-3001-BL1
18 PVC BLACK TOPCOAT FORMULATION
BASED ON RHOPLEX AC-3001 EMULSION
Materials Pounds Gallons
Cowles Grind
Water 121.8 14.62
Natrasol™ 250MR 1.1 0.10
Ammonia (28%) 0.5 0.07
TAMOL 731 (25%) 12.1 1.31
Nopco NXZ 3.8 0.51
Bayferrox™ 318M 174.5 4.55
WG-325 Mica 48.3 2.06
Letdown
RHOPLEX AC-3001 (48%) 605.1 68.92
Ethylene glycol monobutyl ether* 43.6 5.81
Surfynol 104E 3.2 0.41
Water 13.7 1.64
Totals 1027.7 100.00
Formulation Constants
PVC, % 18
Volume solids, % 37.9
Weight solids, % 50.0
pH, Adjust with NH4OH (14%) to: approx. 9.0
Viscosity, #4 Ford cup, seconds 18
Coalescent*, % on polymer solids 15
VOC, g/L 119.8
VOC, lb/gal 1.0
Note, this level of coalescent is recommended for ambient drying conditions. Elevated
preheat or postheat temperatures would diminish or possibly eliminate the need for
coalescent.
FORMULATION TC-3001-BR1
15 PVC BROWN TOPCOAT FORMULATION
BASED ON RHOPLEX AC-3001 EMULSION
Materials Pounds Gallons
Cowles Grind
Water 84.2 10.11
Natrasol™ 250HHR 0.7 0.06
Ammonia (28%) 0.4 0.05
TAMOL 731 (25%) 8.4 0.91
Nopco NXZ 2.1 0.28
Ti-Pure R-960 1.4 0.04
Bayferrox 318M 76.6 2.00
Bayferrox 130M 17.5 0.43
Bayferrox 3420 10.4 0.31
WG-325 Mica 62.6 2.67
Letdown
RHOPLEX AC-3001 (48%) 620.5 70.67
Ethylene glycol monobutyl ether* 43.8 5.83
ACRYSOL RM-825 (25%) 0.9 0.09
Water 54.6 6.55
Totals 984.1 100.00
Formulation Constants
PVC, % 15
Volume solids, % 37.5
Weight solids, % 47.5
pH, Adjust with NH4OH (14%) to: approx. 9.0
Viscosity, #4 Ford cup, seconds 20
Coalescent*, % on polymer solids 15
VOC, g/L 119.8
VOC, lb/gal 1.0
Note, this level of coalescent is recommended for ambient drying conditions. Elevated
preheat or postheat temperatures would diminish or possibly eliminate the need for
coalescent.
FORMULATION TC-3001-BR2
25 PVC BROWN TOPCOAT FORMULATION
BASED ON RHOPLEX AC-3001 EMULSION
Materials Pounds Gallons
Cowles Grind
Water 133.5 16.03
Natrasol 250HHR 1.1 0.10
Ammonia (28%) 0.6 0.08
TAMOL 731 (25%) 13.3 1.44
Nopco NXZ 3.3 0.44
Ti-Pure R-960 2.2 0.07
Bayferrox 318M 121.5 3.17
Bayferrox 130M 38.6 0.95
Bayferrox 3420 16.5 0.48
WG-325 Mica 99.4 4.24
Letdown
RHOPLEX AC-3001 (48%) 523.3 59.51
Ethylene glycol monobutyl ether* 25.1 5.01
ACRYSOL RM-825 (25%) 1.3 0.14
Water 82.2 8.34
Totals 1061.9 100.00
Formulation Constants
PVC, % 25
Volume solids, % 35.9
Weight solids, % 50.0
pH, Adjust with NH4OH (14%) to: approx. 9.0
Viscosity, #4 Ford cup, seconds 20
Coalescent*, % on polymer solids 15
VOC, g/L 107.8
VOC, lb/gal 0.9
Note, this level of coalescent is recommended for ambient drying conditions. Elevated
preheat or postheat temperatures would diminish or possibly eliminate the need for
coalescent.
FORMULATION TC-3001-GR1
20 PVC GREEN TOPCOAT FORMULATION
BASED ON RHOPLEX AC-3001 EMULSION
Materials Pounds Gallons
Cowles Grind
Water 102.3 12.28
Natrasol 250HHR 0.9 0.08
Ammonia (28%) 0.5 0.07
TAMOL 731 (25%) 11.2 1.22
Nopco NXZ 2.8 0.37
Ti-Pure R-960 121.8 3.77
Chrome Oxide Green, GN-M 16.4 0.38
Bayferrox 318M 1.9 0.05
Bayferrox 3420 4.7 0.14
WG-325 Mica 84.3 3.59
Letdown
RHOPLEX AC-3001 (48%) 608.2 69.27
Ethylene glycol monobutyl ether* 43.8 5.83
Water 24.6 2.95
Totals 1023.4 100.00
Formulation Constants
PVC, % 20
Volume solids, % 39.3
Weight solids, % 51.0
pH, Adjust with NH OH (14%) to: approx. 9.0
4
Viscosity, #4 Ford cup, seconds 17
Coalescent*, % on polymer solids 15
VOC, g/L 119.8
VOC, lb/gal 1.0
Note, this level of coalescent is recommended for ambient drying conditions. Elevated
preheat or postheat temperatures would diminish or possibly eliminate the need for
coalescent.