U.S. patent application number 12/636502 was filed with the patent office on 2010-06-24 for polyamide sheet silicate compositions.
This patent application is currently assigned to EMS-PATENT AG. Invention is credited to Manfred HEWEL, Botho HOFFMANN, Georg STOEPPELMANN.
Application Number | 20100159175 12/636502 |
Document ID | / |
Family ID | 40443788 |
Filed Date | 2010-06-24 |
United States Patent
Application |
20100159175 |
Kind Code |
A1 |
STOEPPELMANN; Georg ; et
al. |
June 24, 2010 |
POLYAMIDE SHEET SILICATE COMPOSITIONS
Abstract
The invention relates to polyamide sheet silicate compositions,
containing an untreated clay mineral and a water-soluble polyamide,
the concentration of the clay material being greater than 30% by
weight. Furthermore the invention relates to nanocomposites which
contain clay minerals distributed homogeneously in a
water-insoluble thermoplastic matrix. These nanocomposites are
produced by mixing the polyamide sheet silicate composition and a
water-insoluble thermoplastic in the melt.
Inventors: |
STOEPPELMANN; Georg;
(Bonaduz, CH) ; HOFFMANN; Botho; (Domat/Ems,
CH) ; HEWEL; Manfred; (Domat/Ems, CH) |
Correspondence
Address: |
GREENBLUM & BERNSTEIN, P.L.C.
1950 ROLAND CLARKE PLACE
RESTON
VA
20191
US
|
Assignee: |
EMS-PATENT AG
Domat/Ems
CH
|
Family ID: |
40443788 |
Appl. No.: |
12/636502 |
Filed: |
December 11, 2009 |
Current U.S.
Class: |
428/36.9 ;
524/445; 524/446; 524/447; 524/451 |
Current CPC
Class: |
Y10T 428/1397 20150115;
C08K 9/08 20130101; Y10T 428/1372 20150115; C08K 3/346 20130101;
Y10T 428/139 20150115 |
Class at
Publication: |
428/36.9 ;
524/445; 524/447; 524/451; 524/446 |
International
Class: |
C08K 3/34 20060101
C08K003/34; B32B 1/08 20060101 B32B001/08 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 12, 2008 |
EP |
08 021 677.3 |
Claims
1. Clay material, comprising: at least one sheet silicate which is
treated with at least one water-soluble polyamide, at least one
water-soluble copolyamide, and/or at least one water-soluble block
copolyamide, wherein the proportion of sheet silicate, relative to
the entire clay material, is from more than 30% by weight to 60% by
weight.
2. Clay material according to claim 1, wherein the at least one
water-soluble polyamide, at least one water-soluble copolyamide,
and/or at least one water-soluble block copolyamide is selected
from water-soluble polyether amides.
3. Clay material according to claim 2, wherein the water-soluble
polyether amides are polyether amides which can be produced by
polycondensation of a) at least one aliphatic, cycloaliphatic
and/or aromatic dicarboxylic acid with 6 to 36 C atoms, and b) at
least one aliphatic, cycloaliphatic and/or aromatic diamine with 2
to 36 C atoms, and/or c) at least one diamine selected from
diethylene glycol diamine, triethylene glycol diamine,
tetraethylene glycol diamine, 4,7,10-trioxa-1,13-tridecane diamine,
4,7,10,13-tetraoxa-1,16-hexadecane diamine, and d) at least one
polyalkylene glycol diamine, and/or e) lactams and/or
aminocarboxylic acids.
4. Clay material according to claim 3, wherein the at least one
polyalkylene glycol diamine is selected from polyethylene glycol
diamines, polypropylene glycol diamines, and polytetraethylene
diamines.
5. Clay material according to claim 3, wherein the aminocarboxylic
acids are .omega.-aminocarboxylic acids with 5 to 12 C atoms.
6. Clay material according to claim 1, wherein that the at least
one water-soluble polyamide is a polycondensate comprising a) at
least one aliphatic, cycloaliphatic and/or aromatic dicarboxylic
acid with 6 to 36 C atoms; and b) at least one diamine selected
from diethylene glycol diamine, triethylene glycol diamine,
tetraoxahexadecane diamine, tetraethylene glycol diamine,
trioxamidecane diamine, or at least one polyalkylene glycol
diamine.
7. Clay material according to claim 1, wherein the relative
solution viscosity .eta..sub.rel of the at least one water-soluble
polyamide, of the at least one water-soluble copolyamide, and/or of
the at least one water-soluble block copolyamide is between 1.3 and
3.0.
8. Clay material according to claim 1, wherein the sheet silicate
proportion, relative to the entire clay material, is 34 to 55% by
weight.
9. Clay material according to claim 1, wherein the proportion of
the at least one water-soluble polyamide, of the at least one
water-soluble copolyamide, and/or of the at least one water-soluble
block copolyamide, relative to the total clay material, is 40 to
70% by weight.
10. Clay material according to claim 1, wherein the at least one
sheet silicate is selected from vermiculite, talcum and/or
smectite.
11. Clay material according to claim 8, wherein the smectite is
selected from sodium montmorillonite, magnesium montmorillonite,
calcium montmorillonite, aluminium montmorillonite, nontronite,
beidellite, volkonskoite, hectorite, saponite, sauconite,
sobockite, stevensite, svinfordite and/or kaolinite
12. A method for producing a clay material according to claim 1,
comprising a) mixing an aqueous solution of the at least one
water-soluble polyamide, of the at least one water-soluble
copolyamide, and/or of the at least one water-soluble block
copolyamide with an aqueous dispersion of the at least one sheet
silicate; and b) removing the water after a dwell time.
13. The method according to claim 12, wherein a) the mass
concentration of the at least one water-soluble polyamide, of the
at least one water-soluble copolyamide, and/or of the at least one
water soluble block copolyamide in the solution is between 0.2 and
45% by weight, and/or b) the mass concentration of the at least one
sheet silicate in the dispersion is between 0.1 and 20% by
weight.
14. A thermoplastic moulding compound, comprising a clay material
according to claim 1, which is dispersed in a water-insoluble
thermoplastic matrix phase of the moulding compound.
15. A moulding compound according to claim 14, wherein a) the
weight proportion of the clay material, relative to the moulding
compound, is between 1 and 50% by weight, and/or b) the weight
proportion of the matrix phase, relative to the moulding compound,
is between 50 and 99% by weight.
16. A moulding compound according to claim 14, wherein the
thermoplastic matrix phase is selected from polyarylene sulphides,
polylactones, polyesters, polyurethanes, polycarbonates,
poly(meth)acrylates, polysulphones, polysiloxanes, polyamides,
polyether amides, polyester amides and/or mixtures thereof.
17. A moulding compound according to claim 14, further comprising
at least one additive and/or impact modifier.
18. A moulding compound according to claim 17, wherein the
proportion of the at least one additive and/or impact modifier is
0.3 to 30% by weight, relative to the moulding compound.
19. A moulded article, produced from a moulding compound according
to claim 14.
20. A moulded article according to claim 19, for use as a pipe,
fitting, profile for transporting gases, compressed air pipe, foil,
container for packaging purposes, housing for industrial and
consumer goods, or mobile phone housing.
Description
[0001] This application claims priority to EP 08 021 677.3, filed
Dec. 12, 2008, which is incorporated by reference herein in its
entirety.
[0002] The invention relates to polyamide sheet silicate
compositions, containing an untreated clay mineral and a
water-soluble polyamide, the concentration of the clay mineral
being greater than 30% by weight. Furthermore, the invention
relates to nanocomposites which contain clay minerals distributed
homogeneously in a water-insoluble thermoplastic matrix. These
nanocomposites are produced by mixing the polyamide sheet silicate
composition and a water-insoluble thermoplastic in the melt.
[0003] Water-soluble polyamides are known from the state of the
art. Thus U.S. Pat. No. 5,324,812 describes water-soluble
polyamides based on two carboxylic acids, a low-molecular and a
high-molecular polyoxyalkylene diamine. The carboxylic acid mixture
comprises a dicarboxylic acid with 5 to 12 C atoms and a
dicarboxylic acid with 20 to 36 C atoms. Low-molecular ether
diamines such as triethylene glycol diamine or tetraethylene glycol
diamine may be used. The high-molecular polyoxyalkylene diamine
usually contains ethylene oxide radicals, preferably combined with
polyoxypropylene units.
[0004] The swelling of clays with water-soluble polymers is
likewise known in the art. EP 0 747 323 describes intercalates and
exfoliates which, irrespective of the production method, are
produced from sheet silicates and intercalating polymers in the
presence of a liquid carrier. Intercalating polymers, preferably
water-soluble polymers, such as, e.g., PVP and PVA, may be used,
water being used essentially as liquid carrier. In addition,
water-insoluble polymers, such as, e.g., polyamide or polyether,
are also described as intercalating polymers. However, PVA and PVP
are not thermally stable, with decomposition beginning at
temperatures as low as 150 or 200.degree. C. This leads to greatly
discoloured and crosslinked products, as well as extensive
forfeiture of water solubility.
[0005] US 2006/0052505 relates to compositions of water-soluble
polyamides and sheet silicates (clay minerals). Solutions of these
compositions in water are used to produce foils and plates in a
casting process. The resulting flat moulded articles are
recommended for packagings, in particular for chemicals. The clay
minerals are used to control the solution viscosity of the
water-soluble polyamides and compensate for molar mass or
concentration differences of the polyamides in the casting process.
Because of the posed object, i.e., the production of water-soluble
packaging foils, such compositions predominantly contain polyamide
and the viscosity-controlling clay mineral is present clearly in
deficit, i.e. at a concentration of 0.5 to at most 30% by
weight.
[0006] EP 1 312 582 describes clays and also nanocomposites
intercalated with polyether block copolyamides, produced by a
combination of clay, polyether block copolyamide and a
thermoplastic polymer serving as matrix. The intercalation of the
sheet silicate with polyether block copolyamides and the mixing of
these two components with the matrix polymer is effected by means
of melt-mixing, in particular by extrusion. The one-stage extrusion
of all three components is preferred, i.e., without intercalation
of the clay being implemented in advance. Since this method
dispenses with volatile solvents, costly and time-consuming drying
can be dispensed with. However, this method in which the highly
viscous polymer melt and the clay are in contact for only a short
time during the extrusion process (0.5-2 minutes) has the great
disadvantage that the clay is not distributed homogeneously in the
polymer so that clay agglomerates are present in a non-negligible
concentration in the matrix.
[0007] U.S. Pat. No. 5,853,886 describes sheet silicates with
intercalated polymerisable agents for producing crosslinked
nanocomposites, the sheet silicates being converted into the
H.sup.+ form in advance for intercalation with the polymerisable
agents by means of cation exchange. The intercalating polymerisable
agents include low-molecular or at most oligomeric compounds which
carry at least one basic group. During the intercalation, the basic
groups are protonated by the H.sup.+ sheet silicate. If the thus
treated sheet silicates are compounded with thermoplastics which do
not react or which react only a little with the crosslinking-acting
agents, then these low-molecular agents remain in the thermoplastic
matrix. If high processing temperatures are required, the generally
highly reactive and toxic agents are released, form deposits on
tools and lead to undesired subsidiary reactions which impair the
quality of the moulding compound. Such moulding compounds which
contain low-molecular, polymerisable agents have inadequate heat
resistance. For this reason, intercalated sheet silicates of this
type are suitable only for crosslinking polymer systems in which
the low-molecular, functional agents can react and hence become
part of the three-dimensional polymer.
[0008] Furthermore, moulding compounds containing organoclays
(nanocomposites) cause disruptive deposits during injection
moulding processing. Even after a long storage duration, the
finished moulded articles still have the smell of amines which
originate from the so-called Hofmann degradation of quaternary
ammonium compounds.
[0009] The current commercial nanoclays which are all treated with
quaternary ammonium ions all show the above-described disadvantages
due to the Hofmann degradation. Also, the polymer sheet silicate
compositions, which are known to date from the state of the art and
which are based on the water-soluble polymers PVA or PVP, show
inadequate temperature resistance. The thermal decomposition of PVP
begins already at 150.degree. C. whilst PVA is degraded above
200.degree. C. into polyenes. Accompanying the decomposition is the
loss of the original properties. Thus, the decomposition products
are no longer water-soluble and are highly discoloured because of
crosslinkings or altered polarity.
[0010] Since the mixing of nanoclays and the polyamides to be
reinforced must be effected generally at temperatures significantly
above 200.degree. C. or even above 300.degree. C. due to the high
polyamide melting points, thermal damage to the organoclays or to
the clay minerals intercalated with PVA or PVP, including a loss of
quality in the nanocomposite moulding compounds associated
therewith, is unavoidable.
[0011] The present invention provides clay material, containing at
least one sheet silicate which is treated with at least one
water-soluble polyamide, at least one water-soluble copolyamide
and/or at least one water-soluble block copolyamide, characterised
in that the proportion of sheet silicate, relative to the entire
clay material, is more than 30% by weight to 60% by weight.
[0012] In some embodiments, the above-discussed clay material may
be characterised in that the at least one water-soluble polyamide,
at least one water-soluble copolyamide and/or at least one
water-soluble block copolyamide is selected from the group
comprising water-soluble polyether amides, preferably polyether
amides which can be produced by polycondensation of [0013] a) at
least one aliphatic, cycloaliphatic and/or aromatic dicarboxylic
acid with 6 to 36 C atoms, and [0014] b) at least one aliphatic,
cycloaliphatic and/or aromatic diamine with 2 to 36 C atoms, and/or
[0015] c) at least one diamine selected from the group comprising
diethylene glycol diamine, triethylene glycol diamine,
tetraethylene glycol diamine, 4,7,10-trioxa-1,13-tridecane diamine,
4,7,10,13-tetraoxa-1,16-hexadecane diamine, and/or [0016] d) at
least one polyalkylene glycol diamine, in particular polyethylene
glycol diamines, polypropylene glycol diamines, polytetraethylene
diamines, and/or [0017] e) lactams and/or aminocarboxylic acids,
preferably .omega.-aminocarboxylic acids with 5 to 12 C atoms.
[0018] In some embodiments, the above-discussed clay material may
be characterised in that the at least one water-soluble polyamide
is a polycondensate comprising [0019] a) at least one aliphatic,
cycloaliphatic and/or aromatic dicarboxylic acid with 6 to 36 C
atoms, preferably 6 to 24 C atoms, particularly preferred 6 to 12 C
atoms, in particular adipinic acid; and [0020] b) at least one
diamine selected from the group comprising diethylene glycol
diamine, triethylene glycol diamine, tetraoxahexadecane diamine,
tetraethylene glycol diamine, trioxamidecane diamine, or at least
one polyalkylene glycol diamine, in particular polyethylene glycol
diamines, polypropylene glycol diamines, polytetraethylene
diamines; preferably trioxamidecane diamine.
[0021] In some embodiments, the above-discussed clay material may
be characterised in that the relative solution viscosity
.eta..sub.rel of the at least one water-soluble polyamide, of the
at least one water-soluble copolyamide and/or of the at least one
water-soluble block copolyamide is between 1.3 and 3.0, preferably
between 1.4 and 2.0, in particular between 1.5 and 1.9.
[0022] In some embodiments, the above-discussed clay material may
be characterised in that the sheet silicate proportion, relative to
the entire clay material, is of 34 to 55% by weight, particularly
preferred 38 to 52% by weight.
[0023] In some embodiments, the above-discussed clay material may
be characterised in that the proportion of the at least one
water-soluble polyamide, of the at least one water-soluble
copolyamide and/or of the at least one water-soluble block
copolyamide, relative to the total clay material, is of 40 to 70%
by weight, preferably of 45 to 66% by weight, particularly
preferred of 48 to 62% by weight.
[0024] In some embodiments, the above-discussed clay material may
be characterised in that the at least one sheet silicate is
selected from the group comprising vermiculite, talcum and/or
smectites, the smectites being in particular sodium
montmorillonite, magnesium montmorillonite, calcium
montmorillonite, aluminium montmorillonite, nontronite, beidellite,
volkonskoite, hectorite, saponite, sauconite, sobockite,
stevensite, svinfordite and/or kaolinite.
[0025] The present invention also provides methods for producing a
clay material as discussed above, in which [0026] a) an aqueous
solution of the at least one water-soluble polyamide, of the at
least one water-soluble copolyamide and/or of the at least one
water-soluble block copolyamide is mixed with [0027] b) an aqueous
dispersion of the at least one sheet silicate and the water is
removed after a dwell time.
[0028] In some embodiments, the above-discussed methods may be
characterised in that [0029] a) the mass concentration of the at
least one water-soluble polyamide, of the at least one
water-soluble copolyamide and/or of the at least one water soluble
block copolyamide in the solution is between 0.2 and 45% by weight,
preferably between 1.0 and 20% by weight, particularly preferred
between 2.0 and 10% by weight and/or [0030] b) the mass
concentration of the at least one sheet silicate in the dispersion
is between 0.1 and 20% by weight, preferably between 1.0 and 10% by
weight, particularly preferred between 1.5 and 5% by weight.
[0031] The present invention also provides a thermoplastic moulding
compound, containing a clay material which is dispersed in a
water-insoluble thermoplastic matrix phase of a moulding compound
as discussed herein.
[0032] In some embodiments, the above-discussed moulding compound
may be characterised in that [0033] a) the weight proportion of the
clay material, relative to the moulding compound, is between 1 and
50% by weight, preferably between 4 and 33% by weight, particularly
preferred between 5 and 20% by weight, and/or [0034] b) the weight
proportion of the matrix phase, relative to the moulding compound,
is between 50 and 99% by weight, preferably between 67 and 96% by
weight, particularly preferred between 80 and 95% by weight.
[0035] In some embodiments, the above-discussed moulding compound
may be characterised in that the thermoplastic matrix phase is
selected from the group comprising polyarylene sulphides,
polylactones, polyesters, polyurethanes, polycarbonates,
poly(meth)acrylates, polysulphones, polysiloxanes, polyamides,
polyether amides, polyester amides and/or mixtures thereof.
[0036] In some embodiments, the above-discussed moulding compound
may be characterised in that at least one additive and/or impact
modifier is contained, preferably with a weight proportion of 0.3
to 30% by weight, particularly preferred between 0.5 and 20% by
weight, relative to the moulding compound.
[0037] The present invention also provides a moulded article,
producible from the above-discussed moulding compound.
[0038] The present invention also provides for the use of a moulded
article as discussed above as a pipe, fitting, profile for
transporting gases, compressed air pipe, foil, containers for
packaging purposes, housings for industrial and consumer goods or
mobile phone housings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0039] FIG. 1 is a graph showing weight loss of various clay
materials during heating at a rate of 20 k/min to 500.degree. C. in
a nitrogen atmosphere.
[0040] FIG. 2 shows comparative results of heat storage of Example
7 and VB6 at 200 and 220.degree. C.
[0041] It is therefore the object of the present invention to make
available clay materials treated with polyamides (polyamide sheet
silicate compositions or clay materials) with as high as possible
sheet silicate concentration, which have short-term temperature
stability up to 350.degree. C. and hence can also be mixed with
high-melting, thermoplastically processable polymers in the melt
without disadvantageous property losses, such as, e.g., colour loss
or crosslinking in the nanocomposite moulding compounds. The
present invention also avoids the evaporation of toxic, malodorous
or self-igniting gases during compounding. The sheet silicates are
intended to be distributed substantially homogeneously extensively
throughout the nanocomposites according to the invention, so that
in practice no sheet silicate agglomerates are present in the
thermoplastic matrix (in particular polyamide matrix) and so that
moulded articles based on the nanocomposites have high toughness.
Furthermore, the sheet silicates are intended to be able to be used
without complex pretreatment, in particular without preceding
cation exchange.
[0042] This object is achieved with the features of patent claim 1
with respect to the clay material, with the features of patent
claim 12 with respect to the method for producing the clay
material, and also with the features of patent claim 15 with
respect to the thermoplastic moulding compound or more precisely
polyamide sheet silicate concentrate. With patent claims 19 and 20,
moulded articles which can be produced from the thermoplastic
moulding compound and also purposes of use of such moulded articles
are indicated. The respective dependent patent claims thereby
represent advantageous developments.
[0043] According to the invention, hence a clay material,
containing at least one sheet silicate which is treated with at
least one water-soluble polyamide, at least one water-soluble
copolyamide and/or at least one water-soluble block copolyamide is
made available, in which the proportion of sheet silicate, relative
to the entire clay material, is at least 30% by weight. Preferably
untreated sheet silicates are thereby used. In particular, a
preceding cation exchange is dispensed with so that no H.sup.+
sheet silicates are used according to the invention.
[0044] There is termed as "water-soluble" according to the
invention a polyamide which is soluble in pure water, i.e., is
present at the molecular level solvated in water. In particular,
water-solubility is present when at least 10 g, preferably at least
50 g and particularly preferred at least 100 g, polyamide are
completely soluble in 1,000 g water at 23.degree. C., i.e., without
sediment.
[0045] Surprisingly, it was found that a montmorillonite which has
been treated with a water-soluble polyamide has a significantly
higher temperature stability than the commercially available
systems which contain ammonium compounds, so-called organoclays.
Fewer problems due to the so-called Hofmann degradation of
quaternary ammonium compounds hence arise during processing.
Included herein are bad odour and risk of self-ignition of the
resulting degradation products on hot extruder parts.
[0046] In addition, the sheet silicates and nanocomposites treated
with water-soluble polyamide according to the invention display a
significantly lighter colour than the commercial organoclays.
[0047] The polyamide sheet silicate concentrates according to the
invention display a significantly improved temperature stability up
to 350.degree. C., whilst, in the case of the commercial nanoclays,
the degradation begins already from 200.degree. C.
[0048] In a preferred embodiment, the at least one water-soluble
polyamide, at least one water-soluble copolyamide and/or at least
one water-soluble block copolyamide is selected from the group
comprising water-soluble polyether amides, preferably polyether
amides which can be produced by polycondensation of [0049] a) at
least one aliphatic, cycloaliphatic and/or aromatic dicarboxylic
acid with 6 to 36 C atoms, and [0050] b) at least one aliphatic,
cycloaliphatic and/or aromatic diamine with 2 to 36 C atoms, and/or
[0051] c) at least one diamine selected from the group comprising
diethylene glycol diamine, triethylene glycol diamine,
tetraethylene glycol diamine, 4,7,10-trioxa-1,13-tridecane diamine,
4,7,10,13-tetraoxa-1,16-hexadecane diamine, and/or [0052] d) at
least one polyalkylene glycol diamine, in particular polyethylene
glycol diamines, polypropylene glycol diamines, polytetraethylene
diamines, and/or [0053] e) lactams and/or aminocarboxylic acids,
preferably .omega.-aminocarboxylic acids with 5 to 12 C atoms.
[0054] According to the invention, compounds described as
"polymers" specified under point d) are compounds which have 5 to
25 repetition units, i.e. for example penta-, hexa-, hepta-, etc.
-alkylene glycol diamines.
[0055] The water-soluble polyamide concerns in particular a cold
water-soluble polyamide with a relative solution viscosity
(.eta..sub.rel) in the range of 1.3 to 3.0, preferably in the range
of 1.4 to 2.0, in particular in the range of 1.5 to 1.9. There are
used as water-soluble polyamide preferably polyether amides, in
particular with statistical structure. The ether groups situated
between the amide bonds preferably concern oxyethylene units.
[0056] The preferred polyether amides are composed as follows:
[0057] a) aliphatic, cycloaliphatic and aromatic dicarboxylic acids
with 6 to 36 C atoms, [0058] b) aliphatic, cycloaliphatic or
aromatic diamines, [0059] c) diethylene glycol diamine, triethylene
glycol diamine, tetraethylene glycol diamine,
4,7,10-trioxa-1,13-tridecane diamine, [0060] d) polyoxyalkylene
diamines and possibly polyoxypropylene- and/or
polyoxytetramethylene units, the polyoxyethylene units
predominating, [0061] e) lactams or aminocarboxylic acids with 5 to
12 C atoms.
[0062] Molar Ratios:
[0063] a:(b+c+d)=0.8 to 1.2
[0064] if b.noteq.0 then b:(c+d)<0.1 to 0.5
[0065] It is thereby of advantage if the at least one water-soluble
polyamide is a polycondensate comprising [0066] a) at least one
aliphatic, cycloaliphatic and/or aromatic dicarboxylic acid with 6
to 36 C atoms, preferably 6 to 24 C atoms, particularly preferred 6
to 12 C atoms, in particular adipinic acid; and [0067] b) at least
one diamine selected from the group comprising diethylene glycol
diamine, triethylene glycol diamine, tetraethylene glycol diamine,
trioxamidecane diamine, tetraoxahexadecane diamine; or at least one
polyalkylene glycol diamine, in particular polyethylene glycol
diamines, polypropylene glycol diamines, polytetraethylene
diamines; preferably trioxamidecane diamine.
[0068] Polycondensates comprising adipinic acid and trioxamidecane
diamine are hereby used in particular.
[0069] In order to control the molar mass, the relative viscosity
or the flowability or the MVR, there can be added to the batch,
during production of the water-soluble polyamides, copolyamides or
block copolyamides, regulators in the form of monocarboxylic acids
or monoamines. Aliphatic, cycloaliphatic or aromatic monocarboxylic
acids or monoamines, suitable as regulators, are acetic acid,
propionic acid, butyric acid, valeric acid, caproic acid, lauric
acid, stearic acid, 2-ethylhexane acid, cyclohexane acid, benzoic
acid, butylamine, pentylamine, hexylamine, 2-ethylhexylamine,
n-octylamine, n-dodecylamine, n-tetradecylamine, n-hexadecylamine,
stearylamine, cyclohexylamine, 3-(cyclohexylamino)-propylamine,
methylcyclohexylamine, dimethylcyclohexylamine, benzylamine,
2-phenylethylamine, polyalkylene glycol monoamines, trioxamidecane
amine. The regulators can be used individually or in combination.
Also other monofunctional compounds which can react with an amino-
or acid group can be used as regulators, such as anhydrides,
isocyanates, acid halogenides or esters. The normal usage quantity
of the regulators is between 10 and 200 mmol/kg polymer. The molar
mass can be regulated alternatively or also additionally via the
above-indicated molar ratio (a:(b+c+d)=0.8 to 1.2) of the diacids
and diamines.
[0070] In a further advantageous embodiment, the relative solution
viscosity .eta..sub.rel of the at least one water-soluble
polyamide, of the at least one water-soluble copolyamide and/or of
the at least one water-soluble block copolyamide is between 1.3 and
3.0, preferably between 1.4 and 2.0, in particular between 1.5 and
1.9.
[0071] The water-soluble polyamides are hence polymerised-out or
condensed-out macromolecular compounds which are no longer changed
in their structure and molar mass during compounding of the clay
materials according to the invention with thermoplastics.
Polymerisable, polycondensable or crosslinking-acting agents of
low-molecular form are therefore not of concern.
[0072] The water-soluble polyamides according to the invention have
number-average molar masses of at least 5,000 g/mol, preferably of
at least 8,000 g/mol and particularly preferred of at least 10,000
g/mol. The water-soluble polyamides have a number-average molar
mass in the range of 5,000 to 50,000 g/mol, preferably in the range
of 8,000 to 30,000 g/mol and particularly preferred in the range of
10,000 to 25,000 g/mol.
[0073] Further advantages arise if the sheet silicate proportion,
relative to the total clay material, is more than 30 to 60% by
weight, preferably of 34 to 55% by weight, particularly preferred
38 to 52% by weight.
[0074] It is likewise advantageous if the proportion of the at
least one water-soluble polyamide, the at least one water-soluble
copolyamide and/or the at least one water-soluble block
copolyamide, relative to the entire clay material, is of 40 to 70%
by weight, preferably of 45 to 66% by weight, particularly
preferred of 48 to 62% by weight.
[0075] The sheet silicates which are preferably used are thereby
selected from the group comprising vermiculite, talcum and/or
smectites, the smectites being in particular sodium
montmorillonite, magnesium montmorillonite, calcium
montmorillonite, aluminium montmorillonite, nontronite, beidellite,
volkonskoite, hectorite, saponite, sauconite, sobockite,
stevensite, svinfordite and/or kaolinite.
[0076] Sheet silicates in the sense according to the invention
include 1:1- and also 2:1 sheet silicates. In these systems, layers
comprising SiO.sub.4-tetrahedra with those comprising M(O,OH).sub.6
octahedra are crosslinked in a regular manner with each other. M
thereby stands for metal ions such as Al, Mg, Fe. In the case of
the 1:1 sheet silicates, respectively one tetrahedron- and one
octahedron sheet are thereby connected to each other. Examples of
these are kaolin and serpentine minerals.
[0077] In the case of the 2:1 three-sheet silicates, respectively
two tetrahedron sheets are combined with one octahedron sheet. If
all the octahedron places are not occupied with cations of the
required charge for compensation of the negative charge of the
SiO.sub.4 tetrahedron and also of the hydroxide ions, charged
sheets occur. This negative charge is compensated for by the
incorporation of monovalent cations, such as potassium, sodium or
lithium, or bivalent cations, such as calcium, in the space between
the sheets. Examples of 2:1 sheet silicates are talcum,
vermiculites and also smectites, the smectites to which
montmorillonite and hectorite belong inter alia can be easily
swollen with water because of their sheet charge. Furthermore, the
cations are easily accessible for exchange processes or complex
formation.
[0078] The sheet thicknesses of the sheet silicates before swelling
are normally 0.5 nm to 2.0 nm, very particularly preferred 0.8 nm
to 1.5 nm (spacing of the sheet upper edge relative to the
following sheet upper edge). It is hereby possible to increase the
sheet spacing further in that the sheet silicate is converted for
example with the water-soluble polyamides, e.g. at temperatures of
20.degree. C. to 100.degree. C., over a dwell time of generally 0.1
to 24 hours, preferably of 0.1 to 10 hours (swelling). According to
the length of the dwell time and the type of water-soluble
polyamide chosen, the sheet spacing increases in addition by 1 nm
to 15 nm, preferably by 1 nm to 5 nm. The length of the plates is
normally up to 800 nm, preferably up to 400 nm.
[0079] The swellable sheet silicates are characterised by their ion
exchange capacity CEC (meq/g) and their sheet spacing d.sub.L.
Typical values for CEC are at 0.7 to 0.8 meq/g. The sheet spacing
in the case of a dry untreated montmorillonite is at 1 nm and
increases, by swelling with water and applying the water-soluble
polyamide, to values up to 5 nm.
[0080] According to the invention, a method is likewise indicated
for producing the above-mentioned clay material, in which [0081] a)
an aqueous solution of the at least one water-soluble polyamide, of
the at least one water-soluble copolyamide and of the at least one
water-soluble block copolyamide is mixed with [0082] b) an aqueous
dispersion of the at least one sheet silicate and, after a reaction
time (dwell time), the water is removed. The dwell time is 0.5-24
h, preferably 0.5-12 h and particularly preferred 0.5-3 h.
[0083] A preferred embodiment of the method according to the
invention provides that the at least one water-soluble polyamide,
the at least one water-soluble copolyamide and/or the at least one
water-soluble block copolyamide is used with a mass concentration
of the solution between 0.2 and 45% by weight, preferably between
1.0 and 20% by weight, particularly preferred between 2.0 and 10%
by weight.
[0084] It is likewise preferred if the mass concentration of the at
least one sheet silicate in the dispersion is between 0.1 and 20%
by weight, preferably between 1.0 and 10% by weight, particularly
preferred between 1.5 and 5% by weight.
[0085] Furthermore, a thermoplastic moulding compound is made
available according to the invention, which moulding compound
contains a clay material according to the invention which is
dispersed in a water-insoluble thermoplastic matrix phase of the
moulding compound and is mentioned above.
[0086] It is hereby preferred that the weight proportion of the
clay material, relative to the moulding compound, is between 1 and
50% by weight, preferably between 4 and 33% by weight, particularly
preferred between 5 and 20% by weight.
[0087] It is likewise advantageous if the weight proportion of the
matrix phase, relative to the moulding compound, is between 50 and
99% by weight, preferably between 67 and 96% by weight,
particularly preferred between 80 and 95% by weight.
[0088] A preferred composition range is for example: [0089] (a) 1
to 50% by weight polyamide sheet silicate concentrate (preferably:
4 to 33% by weight, in particular 5 to 20% by weight), containing
[0090] (a1) 40 to 70% by weight water-soluble polyamide
(preferably: 45 to 66% by weight, in particular 48 to 62% by
weight) and [0091] (a2) 30 to 60% by weight untreated sheet
silicate (preferably: 34 to 55% by weight, in particular 38 to 52%
by weight) [0092] (b) 50 to 99% by weight thermoplastic
(preferably: 67 to 96% by weight, in particular 80 to 95% by
weight)
[0093] Thermoplastic materials, by way of example, which can serve
as matrix phase of the moulding compound, include the following:
polyarylene sulphides, polylactones, polyesters, polyurethanes,
polycarbonates, poly(meth)acrylates, polysulphones, polysiloxanes,
polyamides, polyether amides, polyester amides and/or mixtures
thereof.
[0094] For example, thermoplastic polymers can be used, such as
polylactones, e.g. poly(pivalolactone), poly(caprolactone) etc.;
polyurethanes which have been produced by reactions of
diisocyanates, such as e.g. 1,5-naphthalene diisocyanate,
p-phenylene diisocyanate, m-phenylene diisocyanate, 2,4-toluene
diisocyanate, 4,4'-diphenylmethane diisocyanate,
3,3'-dimethyl-4,4'-diphenyl-methane diisocyanate, 3,3'
dimethyl-4,4'-biphenyldiisocyanate, 4,4'-diphenylisopropylidene
diisocynate, 3,3'-dimethyl-4,4'-diphenyldiisocyanate,
3,3'-dimethyl-4,4'-diphenylmethane diisocynate,
3,3'-dimethoxy-4,4'-biphenyldiisocyanate, dianisidine diisocyanate,
tolidine diisocyanate, hexamethylene diisocyanate,
4,4'-diisacyanatodiphenylmethane and the like; and linear
long-chain diols, such as e.g. poly(tetramethylene adipate),
poly(ethylene adipate), poly(1,4-butylene adipate), poly(ethylene
succinate), poly(2,3-butylene succinate), polyetherdiols and the
like; polycarbonates, such as e.g.
poly(methane-bis(4-phenyl)carbonate),
poly(1,1-ether-bis(4-phenyl)carbonate),
poly(diphenylmethane-bis(4-phenyl)carbonate),
poly(1,1-cyclohexane-bis(4-phenyl)carbonate),
poly(2,2-bis-(4-hydroxyphenyl)propane) carbonate and the like;
polysulphones; polyamides, such as e.g. poly(4-aminobutyric acid),
poly(hexamethylene adipamide), poly(6-aminohexane acid),
poly(m-xylylene adipamide), poly(p-xylylene sebacamide),
poly(2,2,2-trimethylhexamethylene terephthalamide),
poly(metaphenylene isophthalamide), poly(p-phenylene
terephthalamide), and the like; polyesters, such as e.g.
poly(ethylene azelate), poly(ethylene-1,5-naphthalate),
poly(ethylene-2,6-naphthalate), poly(1,4-cyclohexane dimethylene
terephthalate), poly(ethylene oxybenzoate),
poly(para-hydroxybenzoate), poly(1,4-cyclohexylidene dimethylene
terephthalate), poly(1,4-cyclohexylidene dimethylene
terephthalate), polyethylene terephthalate, polybutylene
terephthalate and the like; poly(arylene oxides), such as e.g.
poly(2,6-dimethyl-1,4-phenyleneoxide),
poly(2,6-diphenyl-1,4-phenylene oxide) and the like; poly(arylene
sulphides), such as e.g. poly(phenylene sulphides) and the like;
polyether imides; vinyl polymers and their copolymers, such as e.g.
polyvinylacetate, polyvinylchlorides, polyvinylbutyral,
polyvinylidene chlorides, ethylene vinylacetate copolymers and the
like; polyacrylates and their copolymers, such as e.g.
polyethylacrylates, poly(n-butylacrylates),
polymethylmethacrylates, polyethylmethacrylates,
poly(n-butylmethacrylates), poly(n-propylmethacrylates),
polyacrylonitrile, polyacrylic acid, ethylene acrylic acid
copolymers, ethylene vinyl alcohol copolymers, acrylonitrile
copolymers, methylmethacrylatestyrene copolymers, ethylene
ethylacrylate copolymers, methacrylated butadienes tyrene
copolymers and the like; ionomers; poly(urethanes), such as e.g.
the polymerisation product of polyols, such as e.g. glycerine,
trimethylolpropane, 1,2,6-hexane triole, sorbitol, pentaerythritol,
polyether polyols, polyester polyols and the like, with one
polyisocyanate, such as e.g. 2,4-toluene diisocyanate, 2,6-toluene
diisocyanate, 4,4'-diphenylmethane diisocyanate, 1,6-hexamethylene
diisocyanate, 4,4-dicyclohexylmethane diisocyanate and the like;
and polysulphones, such as e.g. the reaction product of the sodium
salt of 2,2-bis(4-hydroxyphenyl)propane and
4,4'-dichlorodiphenylsulphone; furan resins, such as e.g.
poly(furan); cellulose ester plastic materials, such as e.g.
cellulose acetate, cellulose acetate butyrate, cellulose propionate
and the like; silicones, such as e.g. poly(dimethylsiloxanes),
poly(dimethylsiloxanes),
poly(dimethylsiloxane-co-phenylmethylsiloxanes) and the like;
polyethers, polyimides; polyvinylidene halides; polycarbonates;
polyphenylene sulphides; polytetrafluoroethylenes; polyacetals;
polysulphonates; polyester-ionomers; polyolefin-ionomers;
copolymers and mixtures of these previously mentioned polymers can
likewise be used.
[0095] Polyamides which can be used in the present invention can be
synthetic, linear polycarbonamides, characterised by the presence
of a repeating carbonamide group as an integral part of the polymer
chain, which are separated from each other by at least two carbon
atoms. Polyamides of this type contain polymers which in general
are known in the state of the art as nylon which is obtained by
diamines and dibasic acids containing the repeating unit,
represented by the general formula
--NHCOR.sup.1COHNR.sup.2--
[0096] R.sup.1 being an alkylene group comprising at least 2 carbon
atoms, preferably 2 to 11, or arylene containing at least 6 carbon
atoms, preferably 6 to 17 carbon atoms; and R.sup.2 being selected
from R.sup.1 and aryl groups. Likewise copolyamides and
terpolyamides can be contained, which are obtained by known
methods, e.g. by condensation of hexamethylene diamine and a
mixture of dibasic acids comprising terephthalic acid and adipinic
acid. The above-described polyamides are known in the state of the
art and comprise for example the copolyamides of 30% hexamethylene
diammonium isophthalate and 70% hexamethylene diammonium adipate,
poly(hexamethylene adipamide) (nylon 6,6) poly(hexamethylene
sebacamide) (nylon 6,10), poly(hexamethylene isophthalamide),
poly(hexamethylene terephthalamide), poly(heptamethylene
pimelamide) (nylon 7,7) poly(octamethylene suberamide) (nylon 8,8),
poly(nonamethylene azelamide) (nylon 9,9) poly(decamethylene
azelamide) (nylon 10,9), poly(decamethylene sebacamide) (nylon
10,10),
poly(bis(4-aminocyclohexyl)methane-1,10-decane-carboxamide)),
poly(m-xylylene adipamide), poly(p-xylylene sebacamide),
poly(2,2,2-trimethylhexamethylene terephthalamide), poly(piperazine
sebacamide), poly(p-phenylene terephthalamide), poly(metaphenylene
isophthalamide) and the like.
[0097] Further suitable polyamides can be polyamides formed by
polymerisation of amino acids and derivatives thereof, such as e.g.
lactams. Examples of these suitable polyamides are
poly(4-aminobutyric acid) (nylon 4), poly(6-aminohexanoic acid)
(nylon 6), poly(7-aminoheptanoic acid) (nylon 7),
poly(8-aminooctanoic acid) (nylon 8), poly(9-aminononanoic acid)
(nylon 9), poly(10-aminodecanoic acid) (nylon 10),
poly(11-aminoundecanoic acid) (nylon 11), poly(12-aminododecanoic
acid) (nylon 12) and the like.
[0098] Preferred polyamides for use in carrying out the present
invention are poly(caprolactam), poly(12-aminododecanoic acid),
poly(hexamethylene adipamide), poly(m-xylylene adipamide) and
poly(6-aminohexanoic acid) and copolymers and/or mixtures thereof,
for their widely extending application.
[0099] In the case of the polyamides, amorphous and partly
crystalline types, aliphatic, cycloaliphatic and partly aromatic
polyamides are preferred. Particularly preferred polyamides thereby
are: PA 6, 66, 69, 610, 612, 614, 46, MXD6-21, MXDI, MXDT, 12, 11,
1010, 1012, 1014, 1212, 4I, 5I, 6I, 8I, 9I, 10I, 12I, 4T, 5T, 6T,
8T, 9T, 10T, 12T, 6-12CHDS, MACM9-18, PACM9-18 and also copolymers
and mixtures thereof, preferably PA 46, 6, 66, 11, 12, MXD6, MXD10,
MXD12, MXDI, MXD6/MXDI, 6T/6I, 6T/66, 6T/10T, 9T and 10T. Also
blends or polymer alloys of the above-mentioned components are
possible.
[0100] The advantageous properties of the clay materials are
particularly useful if the compounding with the matrix polymer
(production of the nanocomposites) is implemented at temperatures
above 200.degree. C., in particular above 240.degree. C. Hence
nanocomposites also with a lower-melting matrix, such as, e.g.,
based on PM11, PA12, PA1010 or PA6, profit from the high
temperature resistance of the clay materials according to the
invention since the production and processing thereof is effected
at temperatures in the range of 220 to 280.degree. C.
[0101] The new polyamide sheet silicate concentrates are used
preferably for the production of nanocomposites based on
higher-melting polyamides which have a melting point of greater
than 240.degree. C., such as, e.g., PA 46, 46/4T, 46/6T, 46/66/6T,
4T/4I/46, 4T/6T, 4T/6T/66, MXD6, PA66, PA6T/66, PA6T/6I,
PA6T/6I/66, PA6T/10T, PAST, PA10T, PA12T, PA11/10T, PA12/10T,
PA10T/1010.
[0102] Further polymers which can be applied in the method of the
present invention are linear polyesters. The type of polyester is
not crucial and the specific polyesters which are selected for use
in a specific situation essentially depend upon the desired
physical properties and features, e.g., the tearing strength, the
modulus, and the like. Hence a large number of linear thermoplastic
polyesters including crystalline and amorphous polyesters which
vary greatly in their physical properties can be suitable for use
in the present invention.
[0103] The specific polyester which is chosen for use can be a
homopolyester or a copolyester or, as desired, a mixture thereof.
Polyesters are normally formed by the condensation of organic
dicarboxylic acids and organic diols and, for this reason,
illustrative examples of suitable polyesters are described further
on with reference to these diols and dicarboxylic acid
precursors.
[0104] Polyesters which can be suitable for use in the present
invention are derived by condensation of aromatic, cycloaliphatic
and aliphatic diols with aliphatic, aromatic and cycloaliphatic
dicarboxylic acids and can be cycloaliphatic, aliphatic or aromatic
polyesters. Examples of suitable cycloaliphatic, aliphatic and
aromatic polyesters which can be used in carrying out the present
invention are poly(ethylene terephthalate), poly(cyclohexylene
dimethylene), poly(ethylene dodecate), poly(butylene
terephthalate), poly(ethylene naphthalate),
poly(ethylene(2,7-naphthalate)), poly(methaphenylene isophthalate),
poly(glycol acid), poly(ethylene succinate), poly(ethylene
adipate), poly(ethylene sebacate), poly(decamethylene azelate),
poly(ethylene sebacate), poly(decamethylene adipate),
poly(decamethylene sebacate), poly(dimethylpropiolactone),
poly(parahydroxybenzoate), poly(ethylene oxybenzoate),
poly(ethylene isophthalate), poly(tetramethylene terephthalate),
poly(hexamethylene terephthalate), poly(decamethylene
terephthalate), poly(1,4-cyclohexane dimethylene terephthalate)
(trans), poly(ethylene-1,5-naphthalate),
poly(ethylene-2,6-naphthalate), poly(1,4-cyclohexylene dimethylene
terephthalate), and poly(1,4-cyclohexylene dimethylene
terephthalate). Polyester components which are produced by the
condensation of a diol and an aromatic dicarboxylic acid are
preferred for use in the present invention.
[0105] Examples of such suitable aromatic carboxylic acids are
terephthalic acid, isophthalic acid and ophthalic acid,
1,3-naphthalene dicarboxylic acid, 1,4 naphthalene dicarboxylic
acid, 2,6-naphthalene dicarboxylic acid, 2,7-naphthalene
dicarboxylic acid, 4,4'-diphenyl dicarboxylic acid,
4,4'-diphenylsulphone dicarboxylic acid,
1,1,3-trimethyl-5-carboxy-3-(p-carboxyphenyl)-idan,
diphenylether-4,4'-dicarboxylic acid, bis-p(carboxyphenyl)methane
and the like. Of the previously mentioned aromatic dicarboxylic
acids, those which are based on a benzene ring (e.g., terephthalic
acid, isophthalic acid, orthophthalic acid) are preferred for use
in carrying out the present invention. Amongst these acid
precursors, terephthalic acid is particularly preferred as acid
precursor since it leads to polyesters which, during the melting
process, are less susceptible to decomposition and are more
dimensionally stable.
[0106] Preferred polyesters for use in practice of the present
invention are poly(ethylene terephthalate), poly(butylene
terephthalate), poly(1,4-cyclohexylene dimethylene terephthalate)
and poly(ethylene naphthalate) and copolymers and mixtures thereof.
Of these selected polyesters, poly(ethylene terephthalate) is
particularly preferred because of its excellent mechanical strength
and producibility.
[0107] It is likewise possible and advantageous that the moulding
compound can contain the normal additives and/or impact modifiers
which are contained preferably with a weight proportion of 0.3 to
30% by weight, particularly preferred between 0.5 and 20% by
weight, relative to the moulding compound.
[0108] The moulding compounds can contain as fillers fibrous or
particulate filling materials in quantities of 5 to 60% by weight,
in particular in quantities of 5 to 50% by weight, per 100 parts by
weight of the nanocomposites (comprising components (a) and (b)).
Examples of suitable fibrous fillers are glass fibres, in
particular E-glass fibres, carbon fibres, metal fibres, potassium
titanate whiskers or aramide fibres. When using glass fibres, these
can be equipped for better compatibility with the matrix material
with a sizing and an adhesive. The carbon- and glass fibres which
are used with a circular cross-section in general have a diameter
in the range of 5 to 20 .mu.m. Flat glass fibres which have a
non-circular, but oval, elliptical, cocoon-like, rectangular or
almost rectangular cross-section have a ratio of the
cross-sectional axes of 2 to 10, in particular of 3 to 5. The
incorporation of round or flat glass fibres can be effected both in
the form of short glass fibres and in the form of endless strands
(rovings).
[0109] Examples of suitable particulate fillers are talcum, mica,
silicate, quartz, titanium dioxide, wollastonite, kaolin, amorphous
silicic acids, magnesium carbonate, magnesium hydroxide, chalk,
lime, feldspar, barium sulphate, glass balls.
[0110] The moulding compounds according to the invention can
contain in addition further supplements. There may be mentioned as
such supplements for example processing aids, stabilisers and
oxidation delayers, agents against heat decomposition and
decomposition by ultraviolet light, lubricants and mould-release
agents, flame protection means, colourants, pigments and
plasticisers.
[0111] According to the invention, a moulded article is likewise
provided which can be produced from a previously described moulding
compound. Purposes of use of such moulded articles are for example
uses as a pipe, fitting, profile for transporting gases, compressed
air pipe, foil, containers for packaging purposes, housings for
industrial and consumer goods or mobile phone housings.
[0112] The present invention is explained in more detail with
reference to the subsequent examples without restricting the
invention to the parameters indicated in the example.
[0113] In the examples and comparative examples, the materials
mentioned subsequently were used:
TABLE-US-00001 PA 12: Grilamid L20, EMS-CHEMIE AG, Switzerland PA
6: Grilon F34, EMS-CHEMIE AG, Switzerland PA66: Radipol A45,
Radici, Italy PA 6T/10T: Grivory HT3, EMS-CHEMIE AG, Switzerland
WL-PA: water-soluble polyamide comprising 4,7,10-
trioxatridecane-1,13-diamine and adipinic acid, according to
example 1 Clay material A: polyamide sheet silicate composition
according to example 2a Clay material B: polyamide sheet silicate
composition according to example 2b Organoclay Cloisite A20, a
montmorillonite treated with quaternary ammonium compounds,
Southern Clay Products Inc., USA Glass fibre Vetrotex 995,
France
[0114] The test pieces were produced on an Arburg injection
moulding unit, the cylinder temperatures for the examples with PA6
and PA12 being in the range of 240.degree. C. to 280.degree. C.
and, for the examples with PA6T/10T, in the range of 300.degree. C.
to 320.degree. C. The moulding temperature with PA6 or PA12 was 60
to 80.degree. C. and, with PA6T/10T, approx. 120.degree. C. The
speed of rotation was chosen such that a screw circumferential
speed of 15 m/min resulted.
[0115] The measurements were implemented according to the following
standards and on the following test pieces.
[0116] Tensile modulus of elasticity, yield stress, elongation
during yield stress: [0117] ISO 527 with a tensile speed of 1
mm/min [0118] ISO tensile test piece, standard: ISO/CD 3167, Type
A1, 170.times.20/10.times.4 mm, temperature 23.degree. C.
[0119] Tearing strength and breaking elongation: [0120] ISO 527
with a tensile speed of 50 mm/min [0121] ISO tensile test piece,
standard: ISO/CD 3167, Type A1, 170.times.20/10.times.4 mm,
temperature 23.degree. C.
[0122] Melting temperature (Tm) [0123] ISO standard 11357-1/-2
[0124] Granulate
[0125] The differential scanning calorimetry (DSC) was implemented
with a heating rate of 20.degree. C./min.
[0126] Relative viscosity: [0127] DIN EN ISO 307, in 0.5% by weight
m-cresol solution, temperature 20.degree. C.
[0128] MVR: (melt volume rate) [0129] according to ISO 1133 at
275.degree. C. and a loading of 5 kg
[0130] HDT A (1.8 MPa) [0131] ISO 75 [0132] ISO impact test piece
80.times.10.times.4 mm
[0133] Ash content:
[0134] The clay mineral concentration in the clay material or
nanocomposite is determined by incineration. For this purpose,
granulate is weighed into a platinum crucible and incinerated in
the muffle-type furnace at 550.degree. C. until weight
constancy.
[0135] TGA:
[0136] The TGA curves were recorded by means of a TA instrument TGA
Q500; the samples were heated in the platinum crucible in a
nitrogen atmosphere at a heating rate of 20 K/mm to 500.degree. C.,
the weight loss being registered.
[0137] If not annotated otherwise in the table, the test pieces are
used in the dry state. For this purpose, the test pieces are stored
in dry surroundings at room temperature for at least 48 h after the
injection moulding.
[0138] The production of the polyamide sheet silicate concentrate
is effected preferably via the aqueous phase, i.e. in the first
step, the aqueous solution of the water-soluble polyamide is
brought together with the sheet silicate or a dispersion of the
sheet silicate in water. The water concentration of the mixture of
water-soluble polyamide, sheet silicate and water is in the range
of 2 to 98% by weight, preferably in the range of 5 to 90% by
weight and particular preferred in the range between 10 and 80% by
weight. After a mixing and swelling phase, the water is withdrawn
by drying. For this purpose, the above solution/dispersion is
evaporated at 80 to 100.degree. C. or subjected to spray drying.
However, it is also possible as an option that, before the actual
drying, a concentration of the aqueous mixture/dispersion is
effected with respect to the treated clay by means of a centrifuge.
Water, but also excess water-soluble polyamide is hereby removed so
that, with this method, also higher-concentrated clay materials,
i.e., with a lower content of water-soluble polyamide, can be
obtained.
[0139] The alternative production of the clay materials is effected
by compounding of the clay materials with the water-soluble
polyamide, no water or only very little being used, such as, e.g.,
2 to 10% by weight relative to the total clay material.
[0140] The added water is removed entirely or partially from the
polyamide sheet silicate composition in the degassing zone of the
extruder so that disturbance-free discharge and granulation of the
moulding compound is ensured.
EXAMPLES FOR PRODUCTION
Example 2A
[0141] Solution 1: 37.5 g of a water-soluble polyamide is dissolved
in 500 g water at room temperature.
[0142] Solution 2: 25 g sheet silicate (Cloisite Na+) are dispersed
in 975 g water with the help of an Ultraturrax and an ultrasonic
bar (10 minutes ultrasound).
[0143] The two solutions A and B are combined, agitated for one
hour and then left to stand for 12 hours.
[0144] By drying at 80.degree. C., the water is removed.
Thereafter, the concentrate is transferred into a form which can be
metered for the compounding by coarse grinding.
[0145] A polyamide sheet silicate concentrate is obtained,
comprising 60% by weight water-soluble polyamide and 40% by weight
sheet silicate.
Example 2B
[0146] The clay material B is produced analogously to example 2A,
Somasif ME100 (CO-OP Chemicals), Japan) being used as clay
mineral.
Nanocomposites
Examples 3 to 7 and Comparative Examples VB3 to VB6
[0147] The nanocomposites according to the invention are obtained
by melt-mixing of thermoplastic polymers with the above-described
polyamide sheet silicate concentrates. The clays treated by means
of the water-soluble polyamide are thereby dispersed homogeneously
in the matrix polymer. Because of the very good swelling properties
of the aqueous polyamide solutions and the excellent compatibility
of the water-soluble polyether amides with many matrix polymers, in
particular with other polyamides, complete dispersion of the clay
particles takes place so that the nanocomposites according to the
invention are virtually free of any clay agglomerates.
[0148] Production
[0149] Water-insoluble polyamide, polyamide sheet silicate
concentrate and any possible additives are metered into the feed of
a constant rotating twin-shaft extruder (WP ZSK 25) and extruded
under the conditions indicated in Table 1 and 2.
Production of the Water-Soluble Polyamide
Example 1
[0150] 59.82 kg adipinic acid, 90.18 kg trioxamidecane diamine and
10 kg water were filled into a reactor, made inert with nitrogen
and heated to 245.degree. C. As soon as this temperature was
reached, the pressure-reduction began. After reaching this
temperature, the reactor was reduced to normal pressure within 1 h.
The polymer melt was maintained then for a further hour with
agitation at 245.degree. C., the reaction water being removed at
normal pressure by passing nitrogen thereover. After compression of
5 bar nitrogen, the reactor contents were discharged through a
nozzle plate. After cooling the polymer strands on a fluidised bed,
the latter were granulated.
[0151] The polyether amide formed had a relative solution viscosity
of 1.93, a COOH end group concentration of 31 mmol/kg and also an
NH.sub.2 end group concentration of 38 mmol/kg and was readily
soluble in cold water.
[0152] FIG. 1 shows the weight loss which various clay materials
suffer during heating at a rate of 20 k/min to 500.degree. C. in
nitrogen (TGA: thermogravimetric analysis). The organoclay Cloisite
A20 (a clay material of the state of the art), a montmorillonite
treated with quaternary ammonium compounds, already suffers a
massive weight loss from 200.degree. C. This means that, above
200.degree. C., decomposition (Hofmann degradation) and evaporation
of the decomposition products takes place. These volatile
decomposition products lead, during processing, to unacceptable
restrictions and quality losses. During injection moulding,
significant deposits arise in the mould and/or on the moulded
articles, for example, even after a few cycles. During the
extrusion of flat foils, such deposits on the withdrawal rolls
cause the formation of holes in the foil.
[0153] In contrast, the clay materials A (example 2A) and B
(example 2B) according to the invention, the montmorillonites
sodium Cloisite (Cloisite Na+) and Somasif ME100 treated with
water-soluble polyamide, are stable up to a temperature of
360.degree. C., i.e., neither decomposition nor evaporation of the
contents occurs.
[0154] The examples and comparative examples show that the
difference in the moduli of elasticity of nanocomposites according
to the invention and the associated matrix is the same or slightly
higher than the difference in the moduli of elasticity of
conventional nanocomposites and of the corresponding matrix. This
means that the clay materials according to the invention effect an
at least equally high reinforcement relative to the underlying
polymer matrix than the clays modified according to the state of
the art. The nanocomposites according to the invention are
distinguished in total by good mechanical and thermal properties.
It was observed in particular that the new nanocomposites have a
tendency to be significantly tougher, which is manifested in a
higher tearing elongation in comparison with the nanocomposites of
the state of the art (e.g., comparison of example 3 with VB3b, the
measured breaking elongations being at 230% or 170%; or comparison
of example 4 with VB4b, the breaking elongations being 40% or 4%).
Granulate and also moulded articles made of the nanocomposites
VB3b, VB4b and VB5b smell unpleasantly of amines, whilst granulate
and moulded articles made of the nanocomposites according to the
invention have a neutral, polyamide-typical smell. It is also
advantageous that, during production and processing of the
nanocomposites according to the invention, no toxic, inflammable
gases are emitted.
TABLE-US-00002 TABLE 1 Examples 3 and 4 and also comparative
examples VB3 and VB4 Composition Unit 3 VB3a VB3b VB3c 4 VB4a VB4b
VB4c PA12 (Grilamid L20) % by weight 89.2 93.2 92.7 99.2 PA6
(Grilon F34) % by weight 89.2 93.2 92.7 99.2 Clay material A % by
weight 10.0 10.0 Organoclay % by weight 6.5 6.5 WL-PA % by weight
6.0 6.0 Heat stabilisation % by weight 0.8 0.8 0.8 0.8 0.8 0.8 0.8
0.8 Compounding Temperature range .degree. C. 230-240 230-240
230-240 230-240 250-260 250-260 250-260 250-260 Screw speed of
rotation rpm 450 450 450 450 450 450 450 450 Degassing mbar 150 150
150 150 150 150 150 150 Compound temperature .degree. C. 260 258
257 260 282 280 281 279 Throughput kg/h 15 15 15 15 15 15 15 15
Properties Melting point .degree. C. 178 -- 178 -- 220 -- 220 --
MVR (270.degree. C./5 kg) cm.sup.3/10 min 24 40 28 40 32 40 31 40
Ash content % by weight 3.8 <0.1 4.1 <0.1 3.8 <0.1 4.0
<0.1 Tensile modulus of elasticity MPa 1930 1500 2050 1600 4100
2800 4400 3200 Yield stress MPa 52 47 50 48 93 72 89 85 Elongation
during yield stress % 5.1 5.1 5 5 4.3 4.3 4.0 4.0 Tearing
resistance MPa 58 54 47 43 20 40 100 51 Breaking elongation % 230
280 170 200 40 80 4 20 HDT A .degree. C. 57 50 50 50 94 65 97 65
Release of amines during -- no no yes no no no yes no extrusion
Mould deposits SPG -- no no yes no no no yes no Clay agglomerate
(light -- practically -- a few -- practically -- a few --
microscopy) none none Smell of the moulded articles -- neutral
neutral of amine neutral neutral neutral of amine neutral
TABLE-US-00003 TABLE 2 Examples 5 to 7 and comparative examples VB5
and VB6 Unit 5 VB5a VB5b VB5c 6 7 VB6 Composition PA6T/10T % by
weight 89.2 93.2 92.7 99.2 PA6 % by weight 37.1 33.2 36.95 PA66 %
by weight 37.1 33.2 36.95 Glass fibre % by weight 15 15 15 Tafmer
MC201 % by weight 5.0 5.0 Clay material A % by weight 10.0 10 12.5
Organoclay % by weight 6.5 5.0 WL-PA % by weight 6.0 Euthylenblack
% by weight 0.75 0.75 Heat stabilisation % by weight 0.8 0.8 0.8
0.8 0.8 0.35 0.35 Compounding Temperature range .degree. C. 300-330
300-330 300-330 300-330 270-290 270-290 270-290 Screw speed of
rotation Upm 400 400 400 400 400 400 400 Degassing mbar 150 150 150
150 150 150 150 Mass temperature .degree. C. 330 330 328 332 285
285 285 Throughput kg/h 15 15 15 15 15 15 15 Properties Melting
point .degree. C. 295 -- 295 -- 260 260 260 MVR (320.degree. C./5
kg) cm.sup.3/10 min 38 80 22 108 -- Ash content % by weight 3.6
<0.1 3.8 <0.1 3.7 Tensile modulus of MPa 4000 2700 3800 3000
6300 6100 5800 elasticity Tearing resistance MPA 82 82 55 70 105 89
59 Breaking elongation % 6 6 5 6 4 2.6 3.0 HDT A .degree. C. 120
105 128 118 195 -- -- Release of amines during -- no no yes no no
no yes extrusion Mould deposits SPG -- no no yes no no no yes Clay
agglomerates -- none -- a few -- none none a few (microscopy) Smell
of the moulded -- neutral neutral of amine neutral neutral neutral
of amine articles The clay materials according to the present
invention not only show an increased stability during processing,
which means that no amines are released, but also exhibit an
increased long-term-resistance. Comparative storing in an oven at
200 and 220.degree. C., respectively with ISO-tension bars (170
.times. 20/10 .times. 4 mm) of the materials according to example 7
and comparative example 6 (see table 2 and FIG. 2) result in a by
far enhanced temperature resistance when using the clay material
according to present invention. Thus, according to example 7, the
primary elongation at rupture according to ISO 527 at 200.degree.
C. and 3000 h and 220.degree. C. and 1500 h, respectively, has been
maintained to a large extend.
* * * * *