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

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.

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.

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.

• PVC window profiles

• Exterior PVC siding

• Railing

• Injection molded parts

Suggested Applications

Impact strength was measured on samples formulated with a standard acrylic impact modifier, Elvaloy® 4924, and Elvaloy® HP661 at 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).

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.

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

Filler Level 15 phr 20 phr 25 phr

Impact Modifier Acrylic Acrylic Elvaloy® 4924 Acrylic Elvaloy® HP661

Failure mode* ductile brittle ductile brittle ductile

$/lb compound $0.597 — $0.584 — $0.580

% 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

DuPont™ Elvaloy® — Rigid PVC Modifiers

Good

None

Dis

per

sio

n

Elvaloy® 4924 Elvaloy® HP661

5.0

4.0

4.5

3.0

3.5

2.0

2.5

0.5

0

1.0

1.5

Acrylic Acrylic Acrylic

15 phr* 20 phr* 25 phr*

Table 2: Thermal degradation during PVC processing at 25 RPMResist 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 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

Table 4: Die Pressure Measurements

Impact Modifier Acrylic Chlorinated PE Elvaloy® 4924 Elvaloy® HP661

Die Pressure (psi) 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.

* All samples were tested until either brittle failure or the capacity of the test was exceeded at 264 lbf.

Figure 1: Comparison of impact modifier effect on filler dispersion

Figure 2: Effect of impact modifiers on filler dispersion

Figure 3: Effect of impact modifiers on surface smoothness

Filler Loading 15 phr 20 phr 25 phr

Impact Modifier Acrylic Acrylic Elvaloy® 4924 Acrylic Elvaloy® HP661

Black Speck* 1.0 1.5 1.0 3.5 1.5

*1 = 0 degradation; 5 = severe degradation

Elvaloy® technology provides toughness and processing benefits enabling higher throughput and cost optimization for your rigid PVC system

Elvaloy® HP661Elvaloy® HP661 Acrylic Impact ModifierAcrylic Impact Modifier

*phr = parts of impact modifier effect on filler dispersion

www.elvaloy.dupont.com

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

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

DuPont™ Elvaloy® — Rigid PVC Modifiers

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.

Copyright © 2009 DuPont or its affiliates. The DuPont Oval Logo, DuPont™, 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.

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 Elvaloy® HP661 there is a potential for higher throughput, while maintaining ductile impact strength.

Formulation 1:

Formulations for filler loading trials*

Formulation 2:

Formulations for processing optimization trials*

PVC 100

Impact Modifier 4

Tin Stabilizer 1

Acrylic Process Aid 1

Calcium Stearate 0.8

Paraffin Wax 1.2

Oxidized Polyethylene 0.2

Calcium Carbonate 15

Titanium Dioxide 1

PVC 100

Impact Modifier 6

Tin Stabilizer 1.3

Acrylic Process Aid 1

Calcium Stearate 0.6

Paraffin Wax 1.2

Glycerol Monostearate 0.4

Oxidized Polyethylene 0.2

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)