Polyamide molding material, production method and accordingly produced molded
body made of the polyamide molding material, and the use thereof as ducts which
come into contact with exhaust gases in motor vehicles
10 The invention relates to a polyamide molding material which can be blowmolded
and has aD increased resistance to acids, in particular to sulfuric acid and acetic acid.
Molded bodies, in particular pipes and hoses, may be produced therefrom by the
method of extrusion blowmolding, which molded bodies can be used because of the
mentioned advantageous properties as ducts, in particular as ducts for air systems
15 which come into contact with exhaust gases in motor vehicles.
Not only the theoretical combustion products CO2 and H20, but rather also, inter
alia, small proportions of acids are found in the exhaust gas of an internal comb!Jstion
engine. The main proportion of these acids is made up by sulfuric acid or, de-
20 pending on the composition of the fuel, also acetic acid. Acetic acid arises, for example,
due to incomplet,e\ oxidation of ethanol, which is often contained in a certain
proportion in the current fuels. The origin of the sulfuric acid in the exhaust gas is
... :1 .
sulfurous fuel compon~ (mercaptans), from which the sulfuric acid arises due to
oxidation processes during the combustion in the engine.
25
The acid-containing exhaust gas becomes a problem, inter alia, if it comes into contact
with a duct made of a plastic which is not acid resistant. Molecular de.5lradation
then begins due to the effect of the acids, whereby the mechanical properties of the
duct can decline until it disintegrates. A representative document from the prior art
30 in regard to this problem is published application DE 199 12 600 Al. Polyoxymethylene
(PaM) is described in this document as a plastic, which is equipped to be acid
stable by adding sterically hindered amines and optionally further stabilizers. Sulfuric
acid, which can form in the engine compartment or exhaust system due to
combustion of sulfurous fuel components, is mentioned in lines 16 to 17 on page 8
35 of DE 199 12 600 Al.
EC-0047P-IN Final
09.04.2013 I WK - 2 -
Pipes made of polyamJde molding material are often used in automobile construction,
because polyamides generally have a good property profile with respect to
mechanical, thermal, and chemical resistance. Thus, for example, EP 2 325 260 Ai
describes a polyamide molding material for producing various pipe systems in the
5 automotive field. Extrusion blowmolding is typically used for producing air guiding
parts, which allows the production of complicated geometries in a low-waste and
cost-effective manner by way of variants such as 3-D blowmolding or suction
blowmolding. The molding materials described in EP 2 325 260 Ai are not suitable
for extrusion blowmolding because of their excessively high melt strength and
10 above all because of the poor surface quality of the component obtained. Only polyamide
r:nolding materials in a specific melt strength rang~ come into consideration
for this purpose. If the melt strength is excessively low, a vertically extruded melt
hose made of polyamide typically tends toward excessively rapid lengthening and
dripping/tearing under the own weight. In contrast, in the event of excessively high
15 melt strength, formation of a hose does not occur, above all, poor surface properties
are observed. A molding material which is capable of blowmolding and is based
on polyether amides (a polyamide elastomer) is described in EP 1 329 481 A2 and
is characterized by a minimum viscosity.
20 In order for.a polyamide molding material to be suitable for producing ducts (Le.,
pipes or hoses) fOr air systems which come into contact with exhaust gas, it must
, be able to be blowmolded,. on the one hand, and it must have a high acid resis-
~ I ,
tance, on the other hal,l&,_.f. Such polyamide molding materials were heretofore unknown.
I •
25
It was therefore the object of the present invention to prOVide a polyamide molding
material which both can be blowmolded and is also acid resistant, and which is
suitable for the production of molded bodies and the use thereof as a duct, in particular
as a duct for air systems, which come into contact with exhaust gases in mo-
30 tor vehicles.
This object is achieved according to the present invention with a polyamide molding
material having the features of Claim 1.
EC-0047P-IN Final
• 09.04.2013 / WK - 3 -
The polyamide moldinp' material according to the invention has the following composition:
(a) 45 - 97.9 wt.-% of a copolyamide, wherein it is synthesized from
(al) at least one diamine selected from the group consisting of 1,6-hexane di-
5 amine, nonane diamine, and 1,10-decane diamine, and
(a2) terephthalic acid, and
(a3) at least one further polyamide-forming monomer selected from the following
group: dicarboxylic acids having 8 - 18 carbon atoms, lactams
having 6 to 12 carbon atoms, amino acids having 6 to 12 carbon atoms,
10 and mixtures thereof;
(b) 2 - ~O wt.-% of at least one impact toughness modifi~r;
(c) 0.1 - 10 wt.-% of at least one viscosity modifier; and
(d) 0 - 35 wt.-% additives and/or filler materials;
wherein the components (a) to (d) add up in total to 100 wt.-% of the polyamide
15 molding material.
Further preferred features and embodiments of the polyamide molding material according
to the invention result from the dependent claims. In addition, a production
method and molded bodies made of the polyamide mplding material, and the use
20 thereof as d,ucts for air systems which come into contact with exhaust gases in motor
vehicles, are claimed.
r~
Possible applications ~e present invention will be explained in greater detail on
the basis of a schematic figure, which is notto restrict the scope of the present in-
25 vention. In the figure:
Figure 1 shows a 3-D view of an automobile engine having turbocharger and air
guiding ducts, which can be produced from the molding material according
to the invention.
30
In a preferred embodiment of the polyamide molding material, 1,6-hexane diamine
and 1,10-decane diamine are selected as the diamines (al), i.e., both at the same
time in combination. When written out, such a polyamide molding material therefore
has the following composition:
35 (a) 45 - 97.9 wt.-% of a copolyamide, wherein it is synthesized from
EC-0047P-IN Final
• 09.04.2013/ WK - 4 -
(a1) l,6-hexane.diamine and l,10-decane diamine, and
(a2) terephthalic acid, and
(a3) at least one further polyamide-forming monomer selected from the following
group: dicarboxylic acids having 8 - 18 carbon atoms, lactams
5 having 6 to 12 carbon atoms, amino acids having 6 to 12 carbon atoms,·
and mixtures thereof;
(b) 2 - 10 wt.-% of at least one impact toughness modifier;
(c) 0.1 - 10 wt.-% of at least one viscosity modifier; and
(d) 0 - 35 wt.-% additives and/or filler materials;
10 wherein the components (a) to (d) add up in total to. 100 wt.-% of the polyamide
molding r:naterial.
A particularly preferred embodiment of the polyamide molding material consists of:
(a) 69 - 90.9 wt.-% of a copolyamide, wherein it is synthesized from
15 (a1) l,6-hexane diamine and l,10-decane diamine, and
(a2) terephthalic acid, and
(a3) at least one further polyamide-forming monomer selected from the following
group: dicarboxylic acids having 8 ;. 18 carbon atoms, lactams.
having 6 to 12 carbon atoms, amino acids having 6 to 12 carbon atoms,
20 alJd mixtures thereof;
(b) 7 - 10 wt.-% of at least one impact toughness modifier;
r(c) 0.1 - 5 wt.-% of at le.ast one viscosity modifier; and
... rl ,
(d) 2 - 16 wt.-% add~es and/or filler materials;
wherein the components (a) to (d) add up in total to tOO wt.-% of the polyamide
25 molding material.
Embodiments of the two above-described formulas, in which the at least one further
polyamide-forming monomer (a3) is dodecane diacid, are very particularly preferred.
With corresponding molar quantity ratios of the monomers, the preferred
30 copolyamide PA 10T/612 is thus obtained.
The copolyamide preferably has a small excess of the acid end groups, but can also
have equalized end groups or a slight excess of the amino end groups.
35
EC-0047P-IN Final
• 09.04.2013/ WK - 5 -
5
10
In a further preferred ,embodiment, the copolyamide has' a relative viscosity of less
than 2.5, preferably less than 2.0, and particularly preferably less than 1.9, determined
according to 150307 as specified under Table 1. However, a minimum relative
viscosity of 1.5 is preferably maintained.
If nonane diamine, which comprises all isomeric diamines having 9 carbon atoms, is
used as the diamine (al), isomer mixtures of the linear isomer n-l,9-nonane diamine
and its branched isomer 2-methyl-l,8-octane diamine are particularly preferred.
In these mixtures, n-l,9-nonane diamine forms the main component.
According to one preferred embodiment of the proposed pqlyamide molding material,
it is characterized in that within the diamines of (al), the proportion of 1,6hexane
diamine makes up 10-40 mol-% and the proportion of 1,10-decane diamine
makes up 60-90 mol-%, and no further diamines are present, and that within the
15 dicarboxylic acids of (a2) and (a3), the proportion of terephthalic acid makes up
60-90 mol-%, and the proportion of further dicarboxylic acid makes up 10-40 mol%,
wherein preferably within (al), the proportion of l,6-hexane diamine makes up
15 - 35 mol-% and the proportion of 1,10-decane diamine makes up 65 - 85 m.ol%,
and within the dicarboxylic acids of (a2) and (a3),.the proportion of terephthalic
20 acid makes !JP 65 - 85 mol-%, and the proportion of further dicarboxylic acid
makes up 15 - 35 mol-%.
I A somewhat more spe1t embodiment is characterized in that in addition to 1,6hexane
diamine and l,10-decane diamine, no further (jiaminesare present within
25 (al), and the proportion of l,o-hexane diamine makes up 15 - 25 mol-% and the
proportion of l,10-decane diamine makes up 65 - 75 mol-%, and that within the
dicarboxylic acids of (a2) and (a3), the proportion of terephthalic acid makes up 65
- 75 mol-%, and the proportion of further acid makes up 15 - 25 mol-%, wherein
the further acid is preferably selected as a dicarboxylic acid having 8 - 18 carbon
30 atoms, and no further polyamide-forming monomers are present in addition thereto.
The C8-C18 dicarboxylic acids used as the component (a3) can be of an aromatic,
aliphatic, and/or cycloaliphatic nature. Suitable aromatic dicarboxylic acids are, for
35 example, isophthalic acid (IPS), suberic acid (C8), azelaic acid (C9), sebacic acid
EC-0047P-IN Final
• 09.04.2013/ WK - 6 -
(C10), undecane diacip (C11), dodecane diacid (C12), brassylic acid (C13), tetradecane
diacid (C14), pentadecane diacid (C15), hexadecane diacid (C16), heptadecanediacid
(C17), octadecane diacid (C18), cis- and/or trans-cyclohexane-1,4dicarboxylic
acid, cis- and/or trans-cyclohexane-1,3-dicarboxylic acid (CHDA),
5 and/or mixtures thereof. The dicarboxylic acid having 8-18 carbon atoms is particularly
preferably selected in this case from the group isophthalic acid, sebacic acid
(C10), undecane diacid (C11), and dodecane diacid (C12), wherein the latter is preferred
in particular.
10 A blend, which is grafted with maleic acid anhydride, of ethylene-propylene copolymer
ang ethylene-butylene copolymer is preferred as the. impact toughness modifier
(b). Such an impact toughness modifier is available under the trade name Tafmer
MC201 from Mitsui Chemical (JP).
15 Further preferred impact toughness modifiers are ionomers. Ionomers have small
quantities of ionic groups bound to a nonpolar polymer chain. For the application,
according to the invention, ionomers produced from the monomers a-olefins, a,13unsaturated
carboxylic acids, and optionally further comonomers are used, wh~rein
the ionomers are entirely or partially neutralized by metal ions. Examples of the a-
20 olefins are ethene, propene, butene, pentene, and hexene, which are used alone or
in combination. E'xamples of the a,13-unsaturated carboxylic acids are acrylic acid,
- rmethacrylic acid, .e.. thacryI,lic, acid, itaconic acid, maleic acid anhydride, maleic acid
monoethyl ester, and Meic acid. The carboxylic acids can be used alone or in
combination, the carboxylic acids acrylic acid and methacrylic acid are preferred.
25 Examples of the comonomers according to the invention are acrylic acid esters, me"'· .
thacrylic acid esters, styrene, norbornene derivatives, etc. Commercial products
are, for example, ACLYN (Honeywell) and Surlyn (DuPont).
In a further embodiment, block polymers of the SEBS type (styrene-ethylene/1-
30 butene/styrene) are used as the impact toughness modifiers (SZM). Preferred SZM
based on styrene monomers (styrene and styrene derivatives) and other vinylaromatic
monomers are also block copolymers synthesized from alkenyl-aromatic
compounds and a conjugated diene as well as hydrogenated block copolymers
made of an alkenyl-aromatic compound and conjugated dienes or combinations of
35 these SZM types. The block copolymer contains at least one block derived from an
EC-0047P-IN Final
• 09.04.2013 / WK - 7 -
alkenyl-aromatic compound and at least one block derived from a conjugated diene.
In the hydrated block copolymers, the proportion of aliphatic unsaturated carbon-
carbon double bonds was reduced by hydrogenation. Two block, three block,
four block, and polyblock copolymers having linear structure are suitable as the
5 block copolymers. However, branched and star-shaped structures are also usable
according to the invention. Branched block copolymers, which are obtained in a
known manner, e.g., by graft reactions of polymer "side branches" onto a polymer
main chain, can also be used.
10 Further preferred impact toughness modifiers are ethylene-vinyl acetate copolymers,
which are grafted with maleic acid anhydride in a particularly preferred embodiment.
A further group of preferred impact toughness modifiers is formed by copolymers
based on polyolefin which contain acrylic acid or methacrylic acid, in particular,
impact toughness modifiers such as acrylic rubbers, e.g., ethylene-glycidyl
15 methacrylate, ethylene acrylic acid ester-glycidyl methacrylate, or so-called MBS or
core-sheath impact modifiers, e.g., based on methacrylate-butadiene-styrene are
mentioned here in particular.
In a preferred embodiment, the impact toughness mo.difiers according to the
20 present invention have a graft proportion of 0.3 to 1.0%, particUlarly preferably 0.4
to 0.8%, and verY particularly preferably 0.5 to 0.6%.
r The impact toughnesstw~difiersof the present invention are used at 2 to 10 wt.-%,
preferably 4 to 10 wt.-%, and particularly preferably, on the one hand,S to 6 wt.-
25 % or alternatively, on the other hand, 6 to 9 wt.-%, in relation to 100 wt.-% of the
polyamide molding material, which is composed of the above-described components
(a) to (d). The sum of all modifiers which increase the impact toughness of
the polyamide molding material according to the invention is preferably not greater
than at most 10 wt.-%.
30
The polyamide molding material according to the invention contains a viscosity
modifier (c), which results in a molecular weight buildup by chain lengthening.of
polyamide molecules during the thermoplastic processing. A preferred variant of a
viscosity modifier is a polycarbonate in an acid-terminated polyamide. Such a vis-
35 cosity modifier is commercially available, for example, under the name BrOggolen®
EC·0047P-IN Final
• 09.04.2013/ WK - 8 -
M 1251 from BruggerT\ann Chemical (Germany) , wherein this is a masterbatch
made of a low-viscosity polycarbonate in an acid-terminated polyamide 6. Another
preferred variant of a viscosity modifier is an acrylic-acid-modified polyethylene of
high density, preferably having a degree of grafting in the range of 5 to 6%. Such a
5 polymer modifier is distributed, for example, by Chemtura under the trade name
Polybond® 1009 and has a degree of grafting of 6%.
Further preferred viscosity modifiers are aromatic polycarbodiimides , which are
distributed, for example, by Rhein-Chemie (Germany) under the name Stabaxol®
10 P. Other preferred viscosity modifiers are acryLic-acid-modified linear polyethylenes
of low density, for example, Okabest® 2400, which is sold ~y OKA-Tec. Further preferred
viscosity modifiers are 1,1'-carbonyl-bis-caprolactamates, which are distributed,
for example, by DSM under the name Allinco® CBC, as well as bisoxazolines,
such as 1,4-phenylene- bis(2-oxazoline).
15
The viscosity modifiers of the present invention are used at 0.1 to 10 wt.-%, preferably
0.1 to 5 wt.-%, and particularly preferably 0.2 to 4 wt.-% in relation to 100
wt.-% of the polyamide molding material, which is composed of the abovedescribed
components (a) to (d).
20
Preferably 1 to 10 wt.-%, particularly preferably 2 to 8 wt.-%, and very particularly
" preferably 2 to 5 .wt.-% of polycarbonates in an acid-terminated polyamide and '
acrylic-acid-modified ~~ethylenes are used as the viscosity,modifiers, in relation
to 100 wt.-% of the polyamide molding material, which is composed of the above-
25 described components (a) to '(d).
Preferably 0.1 to 4 wt.-%, particularly preferably 0.1 to 2 wt.-%, and very particularly
preferably 0.1 to 0.5 wt.-% of 1,1'-carbonyl-bis-caprolactamates and aromatic
polycarbodiimides are used as the viscosity modifiers, in relation to 100 wt.-% of
30 the polyamide molding material, which is composed of the above-described components
(a) to (d).
The viscosity modifiers according to the present invention result during the thermoplastic
processing in a molecular weight buildup by chain lengthening of the po-
EC-0047P-IN Final
09.04.2013/ WK - 9 -
Iyamide molecules anq act fundamentally different than impact toughness modifiers.
The polyamide molding material according to the invention optionally contains additives
and/or fillers (d), which are preferably selected from a group which comprises
5 stabilizers; pigments; colorants; conductivity additives, e.g., carbon black, graphite,
or carbon nanofibrils; flame retardants, in particular halogen-free flame retardants
such as phosphinic acid salts; glass fibers and layered silicates (preferably
montmorillonite). These additives are used at 0 to 35 wt.-%, preferably 0.01 to 20
wt.-%, particularly preferably 1 to 10 wt.-%, and very particularly preferably 1 to 8
10 wt.-% in relation to 100 wt.-% of the polyamide molding material, which is composed
of ~he above-described components (a) to (d).
The polyamide molding material according to the invention is advantageously resistant
to acids, preferably to sulfuric acid and acetic acid. The term polyamide mold-
15 ing material stands for the composition which comprises, in addition to the corresponding
granules, also molded bodies of arbitrary geometry produced therefrom
according to any type of method, in particular also pipes and hoses produced therefrom.
In a preferred embodiment, the mechanical properties after the belowdescribed
storage in acid are not less than 50% of th~ starting values.
20
The polyamide molding material according to the invention can be blowmolded and
, has a melt strength at the applied processing temperature which is preferably in
.. i ,
the range of 35 to 55 fAonds, particularly preferably in the range of 36 to 53
seconds, and very particularly preferably in the range of 37 to 52 seconds. Molding
25 materials having a melt strength outside the mentioned range have the abovementioned
disadvantages with respect to the blowmolding capability. The method
developed by the applicant for measuring the melt strength, for which the abovementioned
preferred ranges for the melt strength apply, will be described hereafter.
30 The preferred method for producing pipe parts from a polyamide molding material
according to the invention is that a polyamide molding material of the described
composition is extrusion blowmolded.
In the method of extrusion blowmolding, the variants 3-D blowmolding or suction
35 blowmolding are preferably applied. A description of the extrusion blowmolding
EC-0047P-IN Final
• 09.04.2013/ WK - 10 -
5
10
process with all comm,on variants, starting with conventional blowmolding via various
3-D technologies up to sequential blowmolding and coextrusion blowmolding, is
found, for example, in the technical data sheet "Processing of Grilamid and Grilon
by Extrusion Blowmolding" from EMS (EMS-GRIVORY) of February 1998.
Molding materials which are suitable for blowmolding can also be processed via
other methods, e.g., injection molding, extrusion, and coextrusion, in the case of
which the melt strength is not important. This also applies to the molding materials
according to the invention.
In gener~_I, the polyamide molding materials according to t.he invention are suitable
for all applications in which blowmolding capability and acid resistance are required.
The preferred use of the molding materials according to the invention, of molded
15 bodies produced therefrom, or of a method for producing molded bodies from such
molding materials is the use for ducts for air systems which come into contact with
exhaust gases in motor vehicles. In particular, in the case of this use, the duct for
air systems is installed in a gasoline engine or diesel engine, and particularly p~eferably
in engines haVing exhaust gas turbochargers..
20
An automobile en'gine having air guiding system is illustrated in exemplary Figure 1.
r \ -
For example, the filtered air duct (3), the charge air flow pipe (4), and/or the
... :i'
charge air return pipe fit can be formed from polyamide molding materials according
to the invention. Engine exhaust gases reach these pipes, for example, via the
25 crankcase ventilation pipe (2)' or through small leaks in the shaft mount of the exhaust
gas turbocharger. In particular, however, the charge air return pipe must
withstand a high acid and temperature stress at the location where, in the case of
exhaust gas recirculation (which is used to reduce the nitrogen oxide formation),
the recirculated exhaust gas partial stream is introduced and admixed. The polya-
30 mide molding material according to the invention or a duct produced therefrom also
comes into consideration, however, for the crankshaft ventilation pipe or possibly
even as the exhaust gas recirculation duct in the region after the exhaust gas recirculation
cooler.
EC-0047P-IN Final
• 09.04.2013 / WK - 11 -
The air gUiding ducts are normally implemented as single-layer. However, they may
also comprise one or more additional layers. Further layers can in principle consist
of all polyamides which adhere to the claimed copolyamide, wherein PA 612, PA
610, PA 12, PA 1010, PA 1012, PA 6, PA 66, and PA 46 are preferred. The polya-
5 mide molding material according to the invention forms the inner layer, which is in
contact with exhaust gas.
The present invention will be described in gr~ater detail on the basis of the following
examples, which illustrate the invention, but are not to restrict the scope of the
10 invention.
The materials listed in following Table 1 were used in the examples and comparative
examples.
15 The molding materials for the examples Bl, B2, and B3, according to the invention,
and for the comparative examples VBl to VB7, were then produced on a two-shaft
extruder from Werner and Pfleiderer, model Z5K25. The proportional amounts of
the starting materials, specified in Table 2 in percent by weight (wt.-%) in relation
to 100 wt.-% of the total molding material, were compounded in the two-shaft ex-
20 truder.
.The mechanical p[opertie,s,and resistance measurements were carried out on injection
molded standard ~t specimens (tension rods). The methods are set forth after
Table 2.
EC-0047P-IN Final
•
Table 1: materials used
Material Trade name Supplier , Relative visco- H20 content
. sitya) [wt.-%]
PA 66 Radipol A45, > Radici 2.7 0.3
PA 6 (A) Grilon F47 EMS-CHEMIE AG 4.0 0.05
PA 6 (B) . Grilon FT_ ~..- EMS-CHEMIE AG 3.0 0.04
PA 10T/612 XE 4201 EMS-CHEMIE AG 1.7 0.05
Impact toughness modifier Tafmer MC201 Mitsui Chem. (JP) - 0.1
Viscosity modifier 1 Polybond 1009 Crompton - 0.2
Viscosity modifier 2 BrOggolen M 1251 BrOggemann - -
Layered silicate Cloisite 20A Rockwood Additives, Southern - <2.5
Clay Products (US)
"
Glass fibers GF Vetrotex 995 Saint-Gobain Vetrotex Deut- - -
EC10-4.5 s~hland GmbH -
Masterbatch for black coloration - BASF, Crompton (US), - -
and heat stabilizationb
) BrOggemann Chem., DSM Andeno,
W. Blythe, Isliker (CH)
a) determined according to ISO 307 (0.5g polyamide in 100 mL m-cresol), calculation of the relative viscosity (RV) according
to RV = t/to based on section 11 of the norm,
b) masterbatch was produced at EMS-CHEMIE AG, and the in~ividual components were acquired from the indicated
suppliers.
EC-0047P-IN Final
......
N
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09.04.2013 / WK
Table 2: composition and mechanical properties
Composition VBl VB2 Bl B2 B3 VB3 VB4 VBS VB6 VB7
PA 66 40.2 - - . - - - - - - -
PA 6 (A) 40.2 - - - - - - - - -
PA 6(B) - 93.25 - - - - - - - -
PA 10.T/6.12 - - '84.15 86.15 71.15 88.15 70.15 93.15 84.15 95.15
Impact toughness modifi- 10.0 0.80 7 9.~ 9.0 9.0 9.0 27 - 13 -
er
Viscosity modifier 1 4.0 4.0 I- .4.0 - 2.0 - - 4.0 - -
Viscosity modifier 2 - - - 2.0 - - - - - 2.0
Cloisite 20A 4.0 - - - - - - - - -
Glass fibers - - - - 15.0 - - - - -
Masterbatch for black co- 1.6 1.95 2.85 2.85 2.85 2.85 2.85 2.85 2.85 2.85
loration and heat stabilization
Mechanical properties
Tensile modulus fMPal 2300 2700 1945 1950 5100 1900 1270 . 2220 1950 2440·
Tear strenqth fMPal 50 50 46 64 103 62 42 64 60 66
Elongation at tear [%] 46 50 13 12 2.5 14 17 4 13 7
Impact toughness Charpy w.b. w.b. _ 80% = w.b., ·w.b. 25 w.b. w.b. 20% = w.b., w.b. w.b.
at 23°C fkJ/m21 20% = 136 80% = 62
Impact toughness Charpy w.b. w.b. 20% = w.b., w.b. 27 w.b. w.b. 50 w.b. w.b.
at -30°C fkJjm21 80% = 56
Notched impact tough- 15 10 48 17 5 51 83 5.9 49 8.2
ness Charpy [kJjm2
] at
23°C
Notched impact tough- 8 8 13 13 4 14 50 6.8 14 7.6
ness Charpy [kJjm2
] at
-30°C
w.b. means: without break
EC-0047P-IN Final
I-"
W
•
5rl";"'}'if,~I·'!"'~~,"g~l(, ,"1- 4<, ,JIWiiii"j.,i, S ,.d, - i..84 A,~ }\4lt4\k ,MA,t.&Q .£ g JA@ L g,",. ,j t" ¥ 2 kg, XQH4itl4i4U.m. a; U .i-WU®.,.,Lt. $ ,k R X ,L#!LMk. 4LW14P'¥@.J¥ Pt;@M.4L,4WV@lP;;e:,J4i ;; 4-M 4- 4 ,",'
- 14 -
Norms for determin\ng the mechanical data
The mechanical data specified in Tables 2 and 4 were determined according to the
following norms.
5 Tensile modulus of elasticity:
ISO 527 using a traction speed of 1 mm/min
ISO tension bar, norm: ISO/CD 3167, type A1, 170 x 20/10 x 4 mm, temperature
23°C.
10 Tear strength and elongation at tear:
ISO ~27 using a traction speed of 50 mm/min in the ca.se of unreinforced materials
and 5 mm/min in the case of reinforced materials
ISO tension bar, norm: ISO/CD 3167, type A1, 170 x 20/10 x 4 mm, temperature
23°C.
15
Impact toughness according to Charpy:
ISO 179/*eU
ISO testing bar, norm: ISO/CD 3167, type B1, 80 x 10 x 4 mm
* 1 = not equipped with instruments at -30°C, 2, = equipped with instruments
20 at 23°C..
,Notched impact to.ughness according to Cl1arpy: ,
ISO 179/*eA ~
ISO testing bar, norm: ISO/CD 3167, type B1, 80 x 10 x 4 mm
25 * 1 = not equipped with fnstruments at -30°C, 2 = equipped with instruments._
at 23°C.
Instructions for acid storage
Resistance to aqueous sulfuric acid (pH 1):
30 The test specimens were placed in a Carius tube (DN80/12-155657, volume = 1L)
and the tube was filled with diluted (diluted with distilled water) sulfuric acid (pH
1), so that the test specimens were immersed" completely in the solution. The Carius
tube was subsequently tightly closed and heated in a furnace to 100°C, and
held at this temperature. After the times specified in Table 4, test specimens were
EC-0047P-IN Final
09.04.2013/ WK
removed and the mec~anical data were ascertained according to the abovespecified
norms.
- 15 -
Resistance to sulfuric acid vapors:
5 200 mm diluted (diluted with distilled water) sulfuric acid (pH 1) was placed in a
Carius tube (DN80j12-155657, volume = 1 L). A grating was placed above this solution
and the test specimens were placed on this grating. The Carius tube was
tightly closed and heated in a furnace to 100°C, and held at this temperature, so
that the test specimens came into contact with the resulting vapors. After the times
10 specified in Table 4, test specimens were removed and the mechanical data which
are also ~pecified in this table were ascertained according ~o the above-indicated
norms.
Resistance to aqueous acetic acid (pH 2):
15 The test specimens were placed in a Carius tube (DN80j12-155657, volume = lL)
and the tube was filled with diluted (diluted with distilled water) acetic acid (pH 2),
so that the test specimens were completely immersed in the solution. Subsequently,
the Carius tube was tightly closed and heated in a furnace to 100°C, and hel.d at
this temperature. After the times specified in Table 4,.the test specimens were re-
20 moved and the mechanical data were ascertained according to the above-specified
norms. , ~
Resistance to acetic a~~apors:
200 mm diluted (diluted with distilled water) acetic acid (pH 2) was placed in a Ca-
25 rius tube (DN80j12-155657,volume = 1 L). A gratin!;j was placed above this solution
and the test specimens were placed on this grating. The Carius tube was tightly
closed and heated in a furnace to 100°C, and held at this temperature, so that the
test specimens came into contact with the resulting vapors. After the times specified
in Table 4, test specimens were removed and the mechanical data which are
30 also specified in this table were ascertained according to the above-indicated
norms.
Melt strength
The melt strength is understood as the "stability under load" (under the own
35 weight) of the preform during the extrusion blowmolding. As already mentioned
EC-0047P-IN Final
• 09.04.2013/ WK - 16 -
above, only molding Illaterials whose melt strength is in a specific range, i.e., in a
suitable processing window, are suitable for extrusion blowmolding. The applicant
has developed his own, practice-related method, according to which it is evaluated
whether the melt strength is in the mentioned range. During this method, a molten
5 hose is continuously extruded via a crosshead. The time which the hose requires to
cover the distance from the die to the floor is used as the measured variable. This
distance is 112 cm in the arrangement used. During the measurement of the melt
strength, a constant output of 100 cm3 molding material melt per minute and a
temperature adapted to the polymer type (see values in Table 3) are used. The
10 time measurement is started at the moment when the melt hose, which continually
exits fr0r'!1 a ring-shaped extrusion die, is cut off at the extrusion die using a spatula.
The time is stopped as soon as the newly exiting hose section, which travels
downward, touches the floor. A material which bears the increasing own weight
(due to the continuously extruded melt) poorly, i.e., begins to stretch in a viscous
15 manner, will lengthen more strongly and thus the tip of the melt hose will touch the
floor earlier, i.e., the shorter measuring time corresponds to a lower melt strength.
The practical advantage of this method for ascertaining the blowmolding capability
is that it is not only based on a single property observed in isolation, such as th.e
molecular weight of the polyamide or a viscosity, but rather all further influencing
20 variables which are relevant for the behavior of the extruded preform melt hos'e are
automatically and integrally incorporated into the measured time.
T ~
Following Tables 3 an~epresent an overview of the experimental studies and results
with respect to blowmolding capability and acid resistance.
25
EC-0047P-IN Final
18.07.2012/ WK / TM
t Table 3: overview of the experimental results, melt strength, and blowmolding capability
Composition VBl VB2 Bl B2 B3 VB3 VB4 VBS VB6 VB7
Melt strength at 260°C [s] X 40 ><><><><><><><>< Melt strength at 280°C [s] 37 ><><><><>< ><><><>< Melt strength at 300°C [s] X >< 52 37 39 17 62 32 22 30
Blowmolding capability +a) ?a) < +a) +a) +a) n.p.b) n.p.b) n.p.b) n.p.b) n.p.b)
- .-- . "-_.- ::, ,,-
Resistance to acetic acid _c) _c) . +d) +d) n.m.e ) n.m.e ) n.m.e ) n.m.e ) n.m.e) n.m.e )
Resistance to sulfuric acid _c) _ c) +d) +d) n.m.e ) n.m.e ) n.m.e) n.m.e ) n.m.e) n.m.e
a) processable,
b) not processable,
c) collapse of the mechanical properties upon storage in acid (see Table 4),
d) mechanical properties maintained> 50% after the storage in acid (see Table 4),
e) not measured.
EC-0047P-IN Final
.......
-.....J
.'
~~~~,.A ¥-.$::;:;:1-.'iUl.. ih, .2 ,.;.\.JLAA,).-,-.'. 3.,kX _-1$. ",,,;',,,.,,)&,;.,11\'$,..,,1 JLX A.-,L,MQ,3V< ~ ~ Tensile modulus [MPal 2300 2890 1945 Tensile modulus rMPal 2300 2890 1945
Tear strenqth rMPal 50 55 - 46 Tear strenqth rMPa] 50 55 46
Elonqation at tear r%1 46 110 13 Elonqation at tear r%1 46 110 13
a1c4idh,(paHt 110)0°C in sulfuric ><'1<><><
Tensile modulus rMPal - 514 (18) 1900 (98) Tensile modulus rMPal - 463 (16) 1374 (70'
Tear strength [MPa] - 44 (80) 42 (91) Tear strenqth rMPal - 42 (76) 38 (83)
Elonqation at tear r%1 - 163 (148) 25 (192) Elonqation at tear r%1 - 184 (167' 44 (340)
a2c5i0d h(paHt 110)0°C in sulfuric><><><><><
Tensile modulus rMPal 0 0 1925 (99) Tensile modulus rMPal 0 585 (20) 990 (51)
Tear strenqth rMPal 0 0 39 (85) Tear strength [MPa1 0 30 (55) 33 (72)
Elonqation at tear r%1 0 0 84 (646) Elonqation at tear r%1 0 46 (42) 9 (69)
14 h at 100°C in sulfuric ><:><>< 14 h at 100°C in acet~. acid vapor (pH 1) ic acid vapor (pH 2) X ><><
Tensile modulus rMPa] - I - 1960 (101) Tensile modulus rMPal - - 1742 (90)
Tear strength rMPal - - - 44 (96) Tear strenqth rMPal - - 42 (91)
Elongation at tear r%1 - - 22 (169) Elonqation at tear r%1 - - 27 (208)
250 h at 100°C in sulfuric><><><250 h at 100°C in .acet-iC><><>< acid vapor (pH 1) ic acid vapor (pH 2)
Tensile modulus rMPal 397 (17) - 1940 (100) Tensile modulus rMPal 0 - 980 (50)
Tear strength rMPal 31 (62) - 39 (85) Tear strength [MPa] 0 - 32 (70)
Elongation at tear r%1 62 (135) - 85 (654) Elonqation at tear r%1 0 - 30 (230)
- means: not determined; 0 means: testing rod broken or cracked;
values in parentheses specify the preservation of the mechanic.al properties in relation to the starting values in percent.
EC-0047P-IN Final
I
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• 18.07.2012/ WK / TM - 19 -
5
Comparative example ~B4 incidentally corresponds to a representative composition
from above-discussed EP 2 325 260 Al. In spite of copolyamide composition which
corresponds per se, however, the material of VB4 was not able to be processed by
blowmolding.
The compositions according to VB1 and VB2 did prove to be capable of blowmolding,
but displayed a strong drop of the mechanical properties after the acid storage.
It is also noteworthy that the comparative materials made of VB1 and VB2 had
higher values for the mechanical properties than the materials according to the in-
10 vention before the acid treatment, but dropped significantly below the values for
the material according to the invention made of B1 after th.e acid storage.
The experiments have thus shown that only the balanced composition according to
the invention of a polyamide molding material having all three obligatory compo-
15 nents in the selected proportional amounts according to Claim 1 is capable of meeting
the stated object in both objects, blowmolding capability and acid resistance.
Good acid resistance with blowmolding capability atthe same time was not to be
expected by a person skilled in the art.
20 Therefore, an advantageous polyamide molding material can be prOVided using this
invention, which may be processed cost-effectively by blowmolding to form molded
r bodies such as pipes and hoses, and which solves the problems that ducts, in par-
... d , .
ticular ducts for air sy~ms which come into contact with exhaust gases in motor
vehicles, made of the heretofore known polyamide blowmolding materials, were at-
25 tacked after a short time by acid vapors. Ducts made' of the present polyamide
molding material accordil'lg to the invention, however, have such an increased acid
resistance that the mechanical properties do not drop below 50% of the starting
values even in the event of strong acid action and therefore a reliable function is
ensured.
30
EC-0047P-IN Final

1. A polyamide molding material having the following composition:
. (a) 45 - 97.9 wt.-% of a copolyamide, wherein it is synthesized from
5 (al) at least one diamine selected from the group consisting of 1,6-hexane diamine,
nonane diamine, and 1,10-decane diamine, and
(a2) terephthalic' acid, and
(a3) at least one further polyamide-forming monomer selected from the following
group: dicarboxylic acids having 8 - 18 carbon atoms, lactams
10 having 6 to 12 carbon atoms, amino.acids having 6 to 12 carbon atoms,
.and mixtures thereof;
(b) 2 - 10 wt.-% of at least one impact toughness modifier;
(c) 0.1 - 10 wt.-% of at least one viscosity modifier; and
(d) a - 35 wt.-% additives and/or filler materials;
15 wherein components (a) to (d) add up in total to 100 wt.-% of the polyamide
molding material.
2. The polyamide molding material according to Claim 1, characterized in t~at
(al) is a combination of 1,6-hexane diamine and 1,10-decane diamine.
20
3. The polyami'de mo,ld\ ing material according to Claim 1 or 2 having the following
composition:
~
(a) 69 - 90.9 w~o of a copolyamide, wherein it is synthesized from
(al) 1,6-hexane diamine and 1,10-decane diamine, and
25 (a2) terephthalic acid, and
(a3) at least one further polyamide-forming monomer selected from the following
group: dicarboxylic acids having 8 - 18 carbon atoms, lactams
having 6 to 12 carbon atoms, amino acids having 6 to 12 carbon atoms,
and mixtures thereof;
30 (b) 7 - 10 wt.-% of at least one impact toughness modifier;
(c) 0.1 - 5 wt.-% of at least one Viscosity modifier; and
(d) 2 - 16 wt.-% additives and/or filler materials;
wherein components (a) to (d) add up in total to 100 wt.-% of the polyamide
molding material.
35
EC-0047P-IN Final
• 09.04.2013/ WK - 21 -
4. The polyamide rT'\0lding material according to Claim 2 or 3, characterized in
that the at least one further polyamide-forming monomer (a3) is dodecane
diacid.
5 5. The polyamide molding material according to one of the preceding claims,
characterized in that the impact toughness modifier (b) is a blend, which is
grafted with maleic acid anhydride, of ethylene-propylene copolymer and
ethylene-butylene copolymer, an ionomer, a block polymer of the SEBS type,
ethylene-vinyl acetate copolymers, or a copolymer based on polyolefin which
10 contains acrylic acid or methacrylic acid. ,.
6. The polyamide molding material according to Claim 1, characterized in that
the impact toughness modifier (b) is used at 4 to 10 wt.-%, preferably, on the
one hand,S to 6 wt.-% or alternatively, on the other hand, 6 to 9 wt.-%, in
15 relation to 100 wt.-% of the polyamide molding material, which is composed
of the above-described components (a) to (d).
7. The polyamide molding material according to one of the preceding claims,
characterized in that the viscosity modifier (c). is selected from the group
20 consisting of a polycarbonate in an acid-terminated polyamide, an acrylic~acidmodified
polyethylene of high density, an aromatic polycarbodiimide, an acrylr
ic-acid-modified linear polyethylene of low-density, 1,l'-carbonyl-bis-
~
caprolactamate,ml,4-phenylene-bis(2-oxazoline).
25 8. The polyamide molding material according to Claim 7, characterized in that.
the viscosity modifier is used at 0.1 to .5 wt.-% and preferably at 0.1 to 4 wt.%
in relation to 100 wt.-% of the polyamide molding material, which is composed
of the above-described components (a) to (d).
30 9. The polyamide molding material according to one of the preceding claims,
characterized in that the additives and/or fillers (d) are selected from a
group which comprises stabilizers; pigments; colorants; conductivity additives
such as carbon black, graphite, and carbon nanofibrils; flame retardants such
as phosphinic acid salts; glass fibers and layered silicates.
35
EC-0047P-IN Final
------ -- -------------
09.04.2013 / WK - 22 -
10. The -polyamide m<1Jlding material according to one of the preceding claims,
characterized i~ that it is resistant to acid, in particular to sulfuric acid and
acetic acid.
5 11. The polyamide molding material according to one of the preceding claims,
characterized in that it can be blowmolded and at the applied processing
temperature has a melt strength in the range of 35 to 55 seconds, preferably
in the range of 36 to 53 seconds, and p9rticularly preferably in the range of 37
to 52 seconds.
10
12. Molded bodies, in particular pipes and hoses, produceEl from a polyamide
molding material according to one of the preceding claims.
13. A method for producing molded bodies, in particular pipes and hoses made of
15 a polyamide molding material, characterized in that a polyamide molding
material according to one of Claims 1 to 11is extrusion blowmolded.
14. The method according to Claim 13, characterized in that 3-D blowmolding
or suction blowmolding is applied during the extrusion blowmolding.
20 ,
15. A use of a pQlyamijde molding material according to one of Claims 1 to 11, of a
molded body~accorcHrig to Claim 12, or of a method for producing molded bodies
according toJ:.tn 13 or 14 for ducts, in particular ducts for air systems
which come into act with exhaust gases in motor vehicles.
25
-16. The use according to Claim 15, characterized in that a duct for air systems
\-
which is in contact with exhaust gases is installed in a gasoline engine or diesel
engine.
30
\. 'Uated this 29/04/2013
(SHRIMANt SINGH)
- OF REMFRY & SAGAR
ATTORNEY FOR THE APPLICANTS -