DuPont™ Elvaloy
®
POLYMER MODIFIER
FOR RIGID PVC COMPOUNDS
DuPont™ Elvaloy® — Rigid PVC Modifiers
DuPont offers a variety of unique
polymer systems designed to
enhance the performance of rigid
PVC compounds and products.
DuPont™ Elvaloy® polymer modifiers
are ethylene, vinyl acetate, carbon
monoxide (E/VA/CO) and ethylene,
n-butyl acrylate, carbon monoxide
(E/nBA/CO) terpolymers, which are
miscible or partially miscible in PVC.
Impact Performance Increases
with Elvaloy® Modifiers
When incorporated into rigid PVC compounds,
Elvaloy® provides good dart drop impact
performance which can be made weatherable.
Although effective when used as the primary
impact modifier, it can be used in combination
with other impact modifiers to balance
viscosity, die swell and cost. Elvaloy® enables
customers to make robust PVC products that
can compete with more expensive polymers.
Reduce your Rigid PVC Cost with
Alternative Impact Modifiers
Impact strength was measured on samples
formulated with a standard acrylic impact
modifier, Elvaloy® 4924, and Elvaloy® HP661 at
Using Elvaloy® impact modifiers, a large
PVC user can expect at least 3% total
materials reduction by increased filler and
reduced additives plus savings from process
improvements.
4 phr* level and extruded at 20–25 RPM
and 190°C.
Table 1 shows the toughness achieved when
increasing the calcium carbonate filler level
from 15 to 20 and 25 phr in a typical rigid PVC
formulation (see Formulation 1, back page).
Formulation Cost Optimization
Higher Filler Loading
One well-known option when trying to lower
rigid PVC costs, is to increase the filler loading
in the formulation. However, with conventional
impact modifiers, you may face difficulties
maintaining both acceptable impact strength
and good surface properties.
Better Finish and Smoother Surface
The same PVC samples as described in section
above (see formulation 1, back page), were
evaluated for undispersed filler particles,
observed as white specks. The improved
compatibility offered with Elvaloy® impact
modifiers is clearly demonstrated in Figure 1
and Figure 2.
Maintain Ductile Impact Strength
With Elvaloy® 4924 and Elvaloy® HP661,
unlike traditional acrylic impact modifiers,
you can increase filler loading in your rigid
PVC compound while maintaining ductile
strength. This provides formulators with new
opportunities for cost reduction.
In addition, thanks to a better compatibility
between the filler and the polymer matrix
when using Elvaloy® impact modifiers, better
surface appearance can be achieved as shown
in Figure 3.
* = parts per hundred resin based on 100 parts of PVC
Table1: Impact strength at increased filler loading
Suggested Applications
• PVC window profiles
Filler Level
15 phr
20 phr
25 phr
Impact Modifier
Acrylic
Acrylic
Elvaloy® 4924
Acrylic
Elvaloy® HP661
• Exterior PVC siding
Failure mode*
ductile
brittle
ductile
brittle
ductile
• Railing
$/lb compound
$0.597
—
$0.584
—
$0.580
• Injection molded parts
% Savings versus Acrylic Control
Control
—
2%
—
3%
* All samples were tested until either brittle failure or the capacity of the test was exceeded at 264 in-lbf .
** Estimates based on typical ingredient costs
Figure 1: Comparison of impact modifier
effect on filler dispersion
15 phr*
20 phr*
Figure 2: Effect of impact modifiers
on filler dispersion
Figure 3: Effect of impact modifiers
on surface smoothness
25 phr*
Good 5.0
4.5
4.0
Dispersion
3.5
3.0
2.5
2.0
1.5
1.0
0.5
None
0
Acrylic
Acrylic
Elvaloy® 4924
Acrylic
Elvaloy® HP661
Acrylic Impact Modifier
Elvaloy® HP661
Acrylic Impact Modifier
Elvaloy® HP661
*phr = parts of impact modifier effect on filler dispersion
Elvaloy® technology provides toughness and processing benefits enabling higher throughput and cost optimization for your rigid PVC system
Resist Black Speck Formation
During these high filler loading trials (see
Formulation 1, back page), when using the
standard acrylic impact modifiers, black specks
were observed within only twenty minutes
of extrusion processing. By comparison, the
samples modified with DuPont™ Elvaloy®
impact modifiers showed no black specks even
after three hours of extrusion.
Lower Stabilizer Content
Due to the high temperatures used in extrusion
processing of rigid PVC compounds, stabilizers
must be added to the formulations to prevent
thermal degradation.
Thanks to their unique nature, Elvaloy® impact
modifiers also act as processing aids, enabling
reductions in processing temperatures of up
to 20°C. Extruding at lower temperatures can
allow formulators to reduce stabilizer content
in their PVC compounds, which in turn reduces
overall system costs.
Elvaloy® technology provides potential for lower
processing temperatures, enabling formulation
cost reduction due to lower stabilizer content.
Processing Cost Optimization
Elvaloy technology offers excellent toughness
as well as opportunities to optimize your
rigid PVC processing conditions such as
lower processing temperature or increased
throughput.
Table 2: Thermal degradation during PVC processing at 25 RPM
Filler Loading
15 phr
Impact Modifier
Black Speck*
20 phr
25 phr
Acrylic
Acrylic
Elvaloy® 4924
Acrylic
Elvaloy® HP661
1.0
1.5
1.0
3.5
1.5
*1 = 0 degradation; 5 = severe degradation
Table 3: Failure Mode (Drop Dart Impact Test*)
Process Temperature
Acrylic
Elvaloy® 4924
Elvaloy® HP661
180°C
ductile
ductile
ductile
170°C
brittle
ductile
ductile
160°C
brittle
brittle
ductile
* All samples were tested until either brittle failure or the capacity of the test was exceeded at 264 lbf .
Table 4: Die Pressure Measurements
Impact Modifier
Die Pressure (psi)
Acrylic
Chlorinated PE
Elvaloy® 4924
Elvaloy® HP661
468
595
464
431
Lower Processing Temperature
In addition to offering toughness improvement,
impact modifiers often have an effect on
extrusion conditions, necessitating the use of
higher process temperatures.
®
When using Elvaloy® HP661 in your rigid PVC
formulation, you can lower your processing
temperatures up to 20°C and maintain ductile
impact strength. This provides opportunities
to optimize your processing costs with
energy savings, shorter cooling times, and
reduced stabilizer content. Processing at lower
temperature also offers improvements in the
dimensional stability and handling of your
extruded PVC product.
Trials were run to evaluate the processing
window for Elvaloy® impact modifiers in
rigid PVC extrusion. Impact strength was
measured on samples formulated according to
Formulation 2 after processing at 180°C, 170°C
and 160°C. The results (see Table 3) clearly
show that Elvaloy® is a suitable replacement
for acrylic impact modifiers, and also provides
opportunities for cost reduction.
DuPont™ Elvaloy® — Rigid PVC Modifiers
Formulation 1:
Formulation 2:
Formulations for filler loading trials*
Formulations for processing optimization trials*
100
PVC
Increased Throughput
Increasing throughput while maintaining
performance is another approach to reducing
processing costs.
In the same processing trials as described
above (see Formulation 2), all the impact
modifiers showed ductile failure at 180°C;
however, lower die pressure was recorded
when using Elvaloy®. This indicates that with
PVC
Impact Modifier
4
Impact Modifier
Tin Stabilizer
1
Tin Stabilizer
Acrylic Process Aid
1
Acrylic Process Aid
6
1.3
1
Calcium Stearate
0.8
Calcium Stearate
0.6
Paraffin Wax
1.2
Paraffin Wax
1.2
Oxidized Polyethylene
0.2
Glycerol Monostearate
0.4
Calcium Carbonate
15
Oxidized Polyethylene
0.2
Titanium Dioxide
1
Calcium Carbonate
2
Titanium Dioxide
9
* Units = phr (parts per hundred resin based on 100 parts of PVC)
* Units = phr (parts per hundred resin based on 100 parts of PVC)
Elvaloy® HP661 there is a potential for higher
throughput, while maintaining ductile impact
strength.
Worldwide DuPont Sales and Support
North America
DuPont
Wilmington, Delaware
Tel +1 302 774 1161
Toll-Free (USA) 800 628 6208
Fax +1 302 999 4399
100
Europe
DuPont de Nemours Int’l. S.A.
Geneva, Switzerland
Tel +41 22 717 51 11
Fax +41 22 717 55 00
Asia
DuPont China Holding Co., Ltd.
Shanghai, China
Tel +86 21 6386 6366
Fax +86 21 6386 6333
www.elvaloy.dupont.com
The data listed here fall within the normal range of properties, but they should not be used
to establish specification limits nor used alone as the basis of design. The DuPont Company
assumes no obligations or liability for any advice furnished or for any results obtained with
respect to this information. All such advice is given and accepted at the buyer’s risk. The
disclosure of information herein is not a license to operate under, or a recommendation to
infringe, any patent of DuPont or others. DuPont warrants that the use or sale of any material
that is described herein and is offered for sale by DuPont does not infringe any patent
covering the material itself, but does not warrant against infringement by reason of the use
thereof in combination with other materials or in the operation of any process.
CAUTION: Do not use in medical applications involving permanent implantation in the human
body. For other medical applications, see “DuPont Medical Caution Statement,” H-50102.
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The miracles of science™, and Elvaloy® are registered trademarks or trademarks
of DuPont or its affiliates. All rights reserved.
K-16359-1 (10/09) Printed in the U.S.A.