Rohm and Haas


PARALOID™ KM-1 Acrylic Impact Modifier
For Weatherable Vinyl Building Applications

Description

PARALOID™ KM-1 Acrylic Impact Modifier belongs to the new generation of The Dow Chemical Company acrylic impact modifiers (AIMs) designed to outperform existing vinyl additives across a range of processing conditions. This new powder modifier provides outstanding impact and rheological performance properties. This unique combination of properties affords conventional AIMs users the opportunity to switch to PARALOID KM-1 Acrylic Impact Modifier with minor or no adjustment to existing formulations.

In addition, the core shell structure of this new modifier has been designed to offer an improved impact strength efficiency satisfying all standards, across a range of processing conditions.

Key Attributes

  • No stress built-up
  • Consistent surface finish (Gloss)
  • Low post-extrusion shrinkage
  • Reduced or no plate-out
  • High impact strength
  • Good resistance to compaction
  • Unparalleled weathering performance

Impact Strength

EN12608 STANDARD
(ISO 179-1/1eA)

Impact strength under plane strain conditions is regarded as a reliable indicator of brittleness for a given formulation, following a linear elastic fracture mechanism on pressed plate. This property is customarily measured with the Single V-notch Impact test (ISO 179-1/1eA). To pass the test, a calendered/pressed formulation must withstand a minimum energy of 20 kJ/m². Results conducted with this procedure demonstrate that PARALOID™ KM-1 Acrylic Impact Modifier provides improved impact strength under plane strain conditions.

As shown in the graph on the following page, PARALOID KM-1 Acrylic Impact Modifier at 6 or 7 phr displays similar or superior impact effectiveness as other acrylic impact modifiers (Fig. 1).

Figure 1: EN 12608 Standard

RAL STANDARD
(DIN 53753: Double V-notch Charpy impact test)

In some countries, reference is made to the RAL-GZ 716/1 Standard. This RAL Standard specifies the use of a double-V notch Charpy impact test (DIN 53753) to measure the impact strength of extruded vinyl profiles under plane stress conditions. A minimum energy of 40 kJ/m² is necessary to satisfy the Standard’s requirements in this regard. Evaluations conducted with this procedure confirm the good efficiency of PARALOID™ KM-1 Acrylic Impact Modifier relative to competitive modifiers (Fig. 2). At low level, PARALOID KM-1 Acrylic Impact Modifier provides enough impact resistance to satisfy the standard.

Figure 2: RAL standard

Process Characteristics

Brabender Rheology

PARALOID™ KM-1 Acrylic Impact Modifier yields a slightly slower fusion but similar fusion temperature, compared to conventional AIMs. Equilibrium torque is comparable to conventional AIMs (Figure 3).

This feature was ascertained in Brabender rheology testing conducted at 180°C and 50 rpm
with a charge weight of 59 grams.

Figure 3: Brabender Rheology Data

.

Loading phr

Fusion time (sec.)

Fusion Temp ºC

Fusion Torque (nm)

Equilibrium Torque (nm)

Pb stabilized formulation

Competitive AIM

6

72

166

16.7

31.6

PARALOID KM-1

6

77

166

20.2

31.5

Extrusion Processing Characteristics

In trials conducted with large parallel or conical twin-screw extruders, vinyl formulations containing PARALOID™ KM-1 Acrylic Impact Modifier exhibit processing characteristics similar or slightly delayed fusion to vinyl formulated with conventional AIMs (Fig. 4). These extruder data reflects the slightly slower fusion observed for PARALOID™ KM-1 Acrylic Impact Modifier in a Brabender test.

Figure 4: Extrusion Characteristics

.

Loading phr

Fusion time (sec.)

Fusion Temp ºC

Fusion Torque (nm)

Equilibrium Torque (nm)

Pb stabilized formulation

Competitive AIM

6

0.671

3.59

1.1

169

PARALOID KM-1

6

0.673

3.43

0.7

166

Competitive AIM

7

0.668

3.64

1.3

171

PARALOID KM-1

7

0.671

3.58

1.0

170

Gloss Properties

As a result of the outstanding rheological and impact properties described above, PARALOID™ KM-1 Acrylic Impact Modifier based formulations delivers very good gloss to vinyl profiles (Fig. 5) compared to competitive AIMs.

Figure 5: 60° Gloss Percentage

Color Properties

As slight temperature adjustment could be required to optimize the PARALOID™ KM-1 Acrylic Impact Modifier efficiency in vinyl profiles, color characteristics remains fully comparable to competitive modifiers (Fig. 6).

Figure 6: b* value

Weatherability

The weathering resistance of vinyl depends on a number of factors in the formulation, notably the polymer grade, the chemical type and concentration of the stabilizer, and the nature of the pigmentation. All acrylic polymers, specially developed by The Dow Chemical Company for vinyl impact modification, have proven their outstanding weathering resistance and color stability over many years. Rigid vinyl products, when properly stabilized, pigmented and modified with PARALOID™ acrylic impact modifiers, show excellent color durability and retention of mechanical properties.

Accelerated weathering tests were carried out with a Xenontest weatherometer for 4000 hours. The tests were performed on window profiles in a Pb stabilized vinyl formulation. The results highlight the excellent long-term durability of PARALOID KM-1 Acrylic Impact Modifier (Fig. 7 and 8).

Figure 7: Color Stability (Delta b*)

Figure 8: Color Stability (Delta E*)

Formulations

Window Profile Ca/Zn Stabilized (K68)

S-PVC K68

100

Ca/Zn-Stabilizerpack

4-6

Titanium Dioxide

5

Calcium Carbonate

5-8

PARALOID™ KM-1

6.0

PARALOID K-125 ER

0.5

Window Profile Pb Stabilized (K68)

S-PVC K68

100

Pb-Stabilizerpack

4-6

Titanium Dioxide

4

Calcium Carbonate

5-8

PARALOID™ KM-1

6.0

PARALOID K-175 ER

0.5

PARALOID K-125 ER

0.5

Packaging and Handling

Packaging and Handling

Powder Characteristics PARALOID™ KM-1 Acrylic Impact Modifier

Funnel flowability, mm

20

Minimum ignition energy, mJ

200-300

Minimum ignition temperature, °C

420

Layer ignition temperature, °C

> 400

KST class/value, Bar.m/s.

Class 1/120

Particle size:

On 0.600 mm, max.

7

On 0.250 mm, max.

60

Through 0.045 mm, max.

25

Handling Precautions

Before using this product, consult the Material Safety Data Sheet (MSDS)/Safety Data Sheet (SDS) for details on product hazards, recommended handling precautions and product storage.

CAUTION! Keep combustible and/or flammable products and their vapors away from heat, sparks, flames and other sources of ignition including static discharge. Processing or operating at temperatures near or above product flashpoint may pose a fire hazard. Use appropriate grounding and bonding techniques to manage static discharge hazards.

CAUTION! Failure to maintain proper volume level when using immersion heaters can expose tank and solution to excessive heat resulting in a possible combustion hazard, particularly when plastic tanks are used.

Storage

Store products in tightly closed original containers at temperatures recommended on the product label.

Disposal

Dispose in accordance with all local, state (provincial) and federal regulations. Empty containers may contain hazardous residues. This material and its container must be disposed in a safe and legal manner.

It is the user's responsibility to verify that treatment and disposal procedures comply with local, state (provincial) and federal regulations. Contact your Dow Plastics Additives Technical Representative for more information

Product Stewardship

Dow has a fundamental concern for all who make, distribute, and use its products, and for the environment in which we live. This concern is the basis for our product stewardship philosophy by which we assess the safety, health, and environmental information on our products and then take appropriate steps to protect employee and public health and our environment. The success of our product stewardship program rests with each and every individual involved with Dow products - from the initial concept and research, to manufacture, use, sale, disposal, and recycle of each product.

Customer Notice

Dow strongly encourages its customers to review both their manufacturing processes and their applications of Dow products from the standpoint of human health and environmental quality to ensure that Dow products are not used in ways for which they are not intended or tested. Dow personnel are available to answer your questions and to provide reasonable technical support. Dow product literature, including safety data sheets, should be consulted prior to use of Dow products. Current safety data sheets are available from Dow.