PARALOID™ KM-355 Acrylic Impact Modifier
For Weatherable Vinyl Building Application
Description
PARALOID KM-355 Acrylic Impact Modifier combines outstanding impact performance with economy of formulation
for extrusion and injection-moulding applications. The enhanced powder properties improve the work-place
environment and facilitate material handling.
For over 30 years, Acrylic Impact Modifiers from Rohm and Haas have contributed to the development and market
recognition of rigid vinyl products, applications range from window frames and housing cladding to garden
furniture and drainage pipes.
PARALOID KM-323B has for many years been a world-wide industry standard, for tensile strength, weatherability
and processability.
The PARALOID KM-334 offers even greater overall performance and, in particular, very high levels of impact
efficiency. PARALOID KM-334 has also become a benchmark for the industry bringing Rohm and Haas a wealth of
scientific and industrial experience in this specialised field.
The development of PARALOID KM-355 represents another major step forward, both in terms of impact efficiency
and overall cost performance. KM-355 is a modifier with a narrow particle size distribution, low dust and odour. Its
synthesis involves a totally new manufacturing approach, and Rohm and Haas has dedicated a plant entirely to
this process, at Grangemouth, in Scotland.
The investment reflects our belief that impact modifiers such as PARALOID KM-355 offer much greater flexibility
than rival technologies, for equivalent performance.
This brochure provides data on some key aspects of PARALOID KM-355's performance, in comparison to the
industry standard PARALOID KM-334: impact performance (both at laboratory and industrial scales),
weatherability, processability, and packaging and handling.
Impact Efficiency
This section illustrates the performance of PARALOID KM-355 on both extruded profiles and mill-moulded plates.
Results indicate that KM-355 performs well both in Pb and Ca/Zn formulations, and at different thicknesses.
Test on Extruded Profiles
Pb Stabilised Vinyl Formulation
In the following tests on extruded profiles using an all-Pb stabilised K68 S-PVC system, KM-355 demonstrates
even better impact resistance than KM-334, and requires lower addition levels. The improvements in impact
performance are seen in both laboratory and industrial profiles.
Laboratory Test Formulation
K68 S-PVC
100.0
Di-basic Pb phosphite
4.0
Neutral Pb stearate
0.5
Ca stearate
0.5
Di-carboxylic acid ester of saturated
aliphatic alcohol
0.6
Fatty acid ester
0.4
Paraffin wax
0.05
TiO2
4.0
CaCO3
4.0
PARALOID impact modifier
as indicated
Rohm and Haas products are tested according to international standards (See test standards).
Single V-Notch Charpy Impact Test (at 23°C)
U-Notch Charpy Impact Test (at 23°C)
Laboratory thickness (mm): 2.90 (KM-355); 3.03 (KM-334)
Industrial thickness (mm): 2.82 (KM-355); 2.83 (KM-334)
Laboratory thickness (mm): 3.01(KM-355), 3.09 (KM-334)
Industrial thickness (mm): 2.86 (KM-355); 2.89 (KM-334)
Double V-Notch Charpy Impact Test
(at different temperatures)
Single V-Notch and U-Notch Charpy Impact Tests
Laboratory thickness (mm): 3.13 (KM-355); 3.14 (KM-334)
Industrial thickness (mm):
KM-355: 2.83 (23°C); 2.78 (10°C); 2.85 (0°C)
KM-334: 2.84 (23°C); 2.85 (10°C); 2.84 (0°C)
V-Notch Charpy:
Thickness (mm): 2.87 (KM-355); 2.97 (KM-334)
U-Notch Charpy:
Thickness (mm): 2.73 (KM-355); 3.01 (KM-334)
V-Notch
Ductility (%)
Laboratory
Ductility (%)
Industrial
23
10
0
23
10
0
KM-355
100
100
16
100
100
100
KM-334
100
33
0
100
100
100
U-Notch
KM-355 KM-334 KM-355
50
0
100
KM-334
50
Tests on Extruded Profiles
Ca/Zn Stabilised Vinyl Formulation
The performance of KM-355 in a Ca/Zn stabilised formulation (with S-PVC K68) is as effective as in the more
traditional Pb stabilised vinyl formulations.
Extrusion Conditions
Temperature (°C)
Screw
120
Barrel 1
170
Barrel 2
180
Die 1
190
Die 2
190
Screw Speed (rpm)
30
Torque (%)
62
Test on Mill-Moulded Plates
Pb stabilised vinyl formulation
The mill-moulding test procedure obtains optimum processing and fusion, allowing the impact modifiers to be
compared under very well controlled conditions.
Single V-Notch Charpy Impact Test
This test shows PARALOID KM-355’s improved impact efficiency, compared to KM-334, while using lower addition
levels.
Impact data were measured on 3 mm mill-moulded plates.
DUCTILITY (%) 5 phr 6 phr 7 phr
KM 355
KM 334
30
8 phr 9 phr
90
90
100
0
10
40
70
Thickness Effect
The thickness of the sample can affect the impact performance of even optimally processed material. The following
test results show that PARALOID KM-355 has higher efficiency than the industry standard KM-334. As thickness is
increased, KM-355 maintains its impact resistance to a significantly greater degree.
U-Notch Charpy Impact Test
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 stabiliser, and the nature of the pigmentation. All-acrylic polymers,
specially developed by Rohm and Haas for vinyl impact modification, have proven their outstanding weathering
resistance and colour stability over many years. Rigid vinyl products, when properly stabilised, pigmented and
modified with PARALOID acrylic impact modifiers, show excellent colour durability and retention of mechanical
properties, notably impact strength.
Natural Weathering
The long-term weathering tests presented below were carried out at Puget-Theniers station in the South of France.
The results of these natural weathering tests for PARALOID KM-355 have already shown the same durability as the
industry standard PARALOID KM-334 in a Pb stabilised vinyl formulation.
Colour Stability - Pb Stabilised Vinyl Formulation
Accelerated Weathering
These accelerated weathering tests were carried out with xenon-arc lighting. The tests were performed on window
profiles in a Pb/Ba/Cd stabilised vinyl formulation. The results highlight the excellent long-term durability of
PARALOID KM-355.
Colour Stability
Impact Retention - Izod ISO-180
Processing and Handling
PARALOID KM-355 exhibits faster fusion characteristics and slightly higher extrusion torque compared to other
PARALOID grades. This allows the reduction of both levels of processing aid and internal lubricant in the
formulation.
Rheology
The Pb/Ba/Cd formulation tests distinguish the fusion characteristics of the two impact modifiers. The Pb
formulation tests show how formulations can be adjusted to give the same performance.
Brabender Performance - Pb/Ba/Cd Stabilised Vinyl Formulation
Pb/Ba/Cd Formulation
K68 S-PVC
100.0
Di-basic Pb phosphite
2.25
Ba Cd laurate
0.75
Neutral Pb stearate
0.3
Ca stearate
0.4
12-Hydroxy stearic acid
0.3
CaCO3
4.0
4.0
TiO2
PARALOID impact modifier
as indicated
Brabender Conditions: 160°C, 50 rpm, 37g
KM-355, 7 phr
KM-334, 7 phr
28
44
Fusion torque (Nm)
28.5
26.0
Equilibrium torque (Nm)
20.5
20.5
30
30
Fusion time(s)
Heat Stability (min)
Brabender Performance - Pb Stabilised Vinyl Formulation
Pb Formulation
K68 S-PVC
100.0
Di-basic Pb phosphite
4.0
Neutral Pb stearate
0.5
Ca stearate
0.5
Di-carboxylic acid ester of saturated
aliphatic alcohol
0.6
Fatty acid ester
0.4
Paraffin wax
0.05
TiO2
4.0
CaCO3
4.0
PARALOID impact modifier
as indicated
Brabender Conditions: 160°C, 50 rpm, 35/36g (constant volume)
KM-355
7 phr
KM-334
7 phr
KM-334
8 phr
0 phr
1 phr
1 phr
84
52
86
Fusion torque (Nm)
21.5
25.5
25
Equilibrium torque (Nm)
20.5
21.5
23.5
Processing Aid
PARALOID K-125
Fusion time(s)
Post-Extrusion Shrinkage
The unique properties of PARALOID KM-355 permit faster fusion with low die swell and, consequently, low postextrusion shrinkage (or reversion). PARALOID KM-355’s low contribution to shrinkage makes it ideal for the faster
extrusion rates of high-quality window profiles.
Samples were extruded on the laboratory scale twin-screw conical extruder KMD-L 25.
Shrinkage (%)
Torque (%)
Melt Pressure (MPa)
Output (kg/h)
KM-355, 7 phr
KM-334, 7 phr
1.12
1.37
72
60
26.5
25.5
9.5
9.6
With some stabiliser/lubricant combinations, it may be desirable to maintain the fusion time when changing from a
more conventional impact modifier to PARALOID KM-355. This still would give the benefits of low die swell and
shrinkage while other features remain constant. A delay in fusion time can usually be achieved by reducing the
processing aid or internal lubricant addition level, thus reducing formulation costs still further.
Packing
Low compaction, combined with a high powder bulk density, allows PARALOID KM-355 to be packed either in deaerated heat-sealed bags, which stack neatly and take up less space, or in easily-handled FIBC semi-bulk units.
PARALOID KM-355’s enhanced powder properties therefore bring advantages in packing and handling.
Aerated Bulk Density (g/cm3)
5-mm Funnel Flow (sec.)
Dust Index (%)
KM-355
KM-334
0.48 - 0.55
0.39 - 0.45
15 - 20
20 - 30
2.5 - 3.5
9 - 10
The low-dusting, free-flow powder characteristics of PARALOID KM-355 have been designed to meet the industry
requirement for easier and safer working operations in automatic handling and feeding systems.
Handling Considerations
Being a powder, PARALOID KM-355 is classified as belonging to the dust explosion class ST1. To ensure safe
handling, the appropriate safety regulations should be observed. We recommend that the prospective user
determine the safe handling procedures necessary for the user’s applications before manufacturing products. A
Material Safety Data Sheet, outlining the hazards and handling methods for individual PARALOID impact modifiers,
is available on request.
Formulations
Three typical window-profile formulations are shown, for Pb, Pb/Ba/Cd and Ca/Zn stabilisation.
Pb Stabilised S-PVC K68
Pb Stabilised S-PVC K68
S-PVC K68
100.0
Pb phosphite
4.00
Neutral Pb stearate
0.50
Ca stearate
0.60
Di-carboxylic acid ester of saturated
aliphatic alcohol
0.50
Fatty acid ester
0.40
12-Hydroxy stearic acid
0.15
TiO2
4.00
CaCO3
7.00
PARALOID KM-355
8.00
Pb/Ba/Cd Stabilised S-PVC K68
Pb/Ba/Cd Stabilised S-PVC K68
S-PVC K68
100.0
Di-basic phosphite
2.25
BaCd laurate
0.75
Neutral Pb stearate
0.30
Ca Stearate
0.40
Fatty acid ester
0.30
12-Hydroxy stearic acid
0.30
TiO2
4.00
CaCO3
4.00
PARALOID KM-355
8.00
Ca/Zn Stabilised S-PVC K68
Ca/Zn Stabilised S-PVC K68
S-PVC K68
100.0
Ca behenate
0.70
Zn Octoate
0.40
Phosphite chelator
0.80
ESBO
0.80
Di beta ketone
0.10
DiTMP
0.20
Di-carboxylic acid ester of saturated
aliphatic alcohol
0.50
Fatty acid ester
0.75
TiO2
5.50
CaCO3
9.50
PARALOID KM-355
8.00
Test Standards
Profiles extruded at a laboratory or industrial scale are tested according to the following international standards.
Test
Standard
Single V-Notch Charpy
BS 7413: BS 2782 /359 (UK)
Double V-Notch Charpy
RAL-RG 716 1 DIN 53753
U-Notch Charpy
RAL-RG 716 1 DIN 53453
Tensile Impact
• DIN 53448
• BS 7413: ISO 8256 (UK)
The PARALOID KM-355 production process has obtained the ISO 9002 quality assurance certification.
PARALOID is a registered trademark of Rohm and Haas Company/Philadelphia (USA).
Rohm and Haas Company makes no warranties, either expressed or implied as to the accuracy or appropriateness of this data and expressly
excludes any liability upon Rohm and Haas arising out of its use.We recommend that the prospective users determine for themselves the
suitability of Rohm and Haas’ materials and suggestions for any use prior to their adoption. Suggestions for uses of our products or the
inclusion of descriptive material from patents and the citation of specific patents in this publication should not be understood as
recommending the use of our products in violation of any patent or as permission or license to use any patents of the Rohm and Haas
Company. Material Safety Data Sheets outlining the hazards and handling methods for our products are available on request.
©Rohm and Haas, 2006
All rights reserved.
September 2003