U.S. patent number RE47,079 [Application Number 15/625,433] was granted by the patent office on 2018-10-09 for process for improving carbon black dispersion.
This patent grant is currently assigned to COVESTRO DEUTSCHLAND AG. The grantee listed for this patent is Covestro Deutschland AG. Invention is credited to Thomas Eckel, Joerg Reichenauer, Reiner Rudolf, Andreas Seidel, Hans-Jurgen Thiem.
United States Patent |
RE47,079 |
Seidel , et al. |
October 9, 2018 |
Process for improving carbon black dispersion
Abstract
A masterbatch comprising pigment and demolding agent is
provided. The demolding agent is selected from the group comprising
low molecular weight polyolefin oils, low molecular weight
polyolefin waxes, montan waxes and aliphatic or aromatic carboxylic
acid esters of fatty acids and/or fatty alcohols, wherein the
pigment content of the masterbatch is from 3 to 70 wt. %, based on
the total weight of the masterbatch. The masterbatch is suitable
for preparation of a polymer composition having improved pigment
dispersion.
Inventors: |
Seidel; Andreas (Dormagen,
DE), Thiem; Hans-Jurgen (Dormagen, DE),
Rudolf; Reiner (Langenfeld, DE), Reichenauer;
Joerg (Krefeld, DE), Eckel; Thomas (Dormagen,
DE) |
Applicant: |
Name |
City |
State |
Country |
Type |
Covestro Deutschland AG |
Leverkusen |
N/A |
DE |
|
|
Assignee: |
COVESTRO DEUTSCHLAND AG
(Leverkusen, DE)
|
Family
ID: |
43877319 |
Appl.
No.: |
15/625,433 |
Filed: |
June 16, 2017 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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Reissue of: |
13332047 |
Dec 20, 2011 |
9056957 |
Jun 16, 2015 |
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Foreign Application Priority Data
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Dec 23, 2010 [EP] |
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10196932 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C08J
3/226 (20130101); C08J 3/226 (20130101); C08L
91/06 (20130101); C08L 91/06 (20130101); C08J
2491/06 (20130101); C08J 2491/06 (20130101) |
Current International
Class: |
C08K
5/10 (20060101); C09D 201/00 (20060101); C08L
91/06 (20060101); C08G 64/16 (20060101); C08J
3/22 (20060101); C09B 67/00 (20060101); C09C
1/44 (20060101) |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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0 578 245 |
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Dec 1994 |
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EP |
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0578245 |
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Dec 1994 |
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EP |
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02/092702 |
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Nov 2002 |
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WO |
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WO 2002/092702 |
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Nov 2002 |
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WO |
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WO 2010/051940 |
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May 2010 |
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WO |
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WO 2010/051940 |
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May 2010 |
|
WO |
|
Other References
International Search Report and Written Opinion for International
Application No. PCT/EP2011/073295, European Patent Office, dated
Feb. 22, 2012. cited by applicant .
Giles, et al., Extrusion: The Definitive Processing Guide and
Handbook, PDL Handbook Series, 2005, pp. 1, 425-430, William Andrew
Publishing/Plastics. cited by applicant .
Giles Extrusion: The Definitive Processesing Guide and Handbook,
2005, William Andrew Publishing/Plastics Design Library., pp. 1,
425-430. cited by examiner .
International Search Report of PCT/EP2011/073295 Mailed Feb. 22,
2012 (13 pages). cited by applicant.
|
Primary Examiner: McKane; Elizabeth
Attorney, Agent or Firm: K&L Gates LLP
Claims
The invention claimed is:
1. An injection molded article produced by a process comprising
.[.preparing.]. .Iadd.injection molding .Iaddend.a coloured polymer
composition .[.by melt-mixing.]., .Iadd. wherein the coloured
polymer composition comprises a melt-mixed coloured polycarbonate
composition, comprising: a) from 40 to 99.96 wt. % of at least one
thermoplastic polymer (a), wherein polymer (a) is at least one
selected from the group consisting of aromatic polycarbonates and
aromatic polyester carbonates, wherein the polymer (a) has a weight
average molecular weight of 15,000 to 80,000 g/mol, and wherein the
polymer (a) is a homopolycarbonate or copolycarbonate containing
bisphenol A; b) from 0.1 to 3 wt. % of at least one pigment
component (b); c) from 0.1 to 3 wt. % of at least one demoulding
agent (c) selected from the group consisting of pentaerythritol
tetrastearate, glycerol monostearate, and stearyl stearate; d) from
0 to 60 wt. % of one or more thermoplastic polyesters (d); e) from
0 to 40 wt. % of one or more elastomers (e) other than component f;
f) from 0 to 40 wt. % of one or more optionally rubber-modified
vinyl (co)polymers (f); and g) from 0 to 10 wt. % one or more
further additives; .Iaddend. .[.the process comprising using a
masterbatch,.]. wherein the .Iadd.melt-mixed coloured polycarbonate
composition comprises a .Iaddend.masterbatch .[.consists.].
.Iadd.consisting .Iaddend.of .Iadd.the .Iaddend.at least one
pigment .Iadd.(b) .Iaddend.and .Iadd.the .Iaddend.at least one
demoulding agent .Iadd.(c) .Iaddend.in compounding .Iadd.prepared
using a shear and mixing unit in a single-shaft extruder, a
multi-shaft extruder, an internal mixer, a co-kneader, or a shear
roller device.Iaddend., .[.wherein the demoulding agent is at least
one selected from the group consisting of pentaerythritol
tetrastearate, glycerol monostearate and stearyl stearate,.].
wherein the .Iadd.at least one .Iaddend.pigment .[.is.]. .Iadd.(b)
comprises .Iaddend.a carbon-based pigment and the content of
pigment in the masterbatch is from 40 to 60 wt. %, based on the
total weight of the masterbatch, wherein the carbon-based pigment
is selected from the group consisting of: a) carbon black; b)
graphite; c) fullerene; d) graphene; e) activated charcoal; and f)
carbon nanotubes.Iadd., and .Iaddend. .[.wherein the process
additionally comprises preparing the masterbatch by using a shear
and mixing unit in a single-shaft extruder, multi-shaft extruder,
internal mixer, co-kneader or a shear roller device,.]. wherein the
pigment is homogeneously distributed and present in finely
dispersed form in the polymer composition.[., wherein the produced
coloured polymer composition is a polycarbonate composition
comprising a) from 40 to 99.96 wt. % of at least one thermoplastic
polymer (a), wherein polymer (a) is at least one selected from the
group consisting of aromatic polycarbonates and aromatic polyester
carbonates, wherein the polymer has a weight average molecular
weight of 15,000 to 80,000 g/mol and is a homopolycarbonate or
copolycarbonate containing bisphenol A b) from 0.1 to 3 wt. % of at
least one pigment component (b), c) from 0.1 to 3 wt. % of at least
one demoulding agent (c) selected from the group consisting of
pentaerythritol tetrastearate, glycerol monostearate and stearyl
stearate, d) from 0 to 60 wt. % of one or more thermoplastic
polyesters (d), e) from 0 to 40 wt. % of one or more elastomers (e)
other than component f, f) from 0 to 40 wt. % of one or more
optionally rubber-modified vinyl (co)polymers (f), and g) from 0 to
10 wt. % one or more further additives.]..
2. An injection molded article according to claim 1, wherein the
pigment is carbon black.
3. An injection molded article according to claim 1, wherein the
.Iadd.masterbatch is prepared by a .Iaddend.process .[.comprises.].
.Iadd.comprising.Iaddend.: a) metering said demoulding agent and
said pigment into said shear and mixing unit, b) melt-mixing the
pigment in the demoulding agent and thereby dispersing the pigment
in the demoulding agent to form a melt mixture, c) optionally
filtering the melt mixture, d) forming melt strands, e) cooling and
granulating the melt strands, and f) when using underwater or
water-ring granulation in step e), drying granules.
4. The injection molded article according to claim 3, wherein the
granulating is carried out by underwater granulation or hot-face
water-ring granulation.
5. An injection molded article according to claim 1 wherein said
pigment is not in powder form.
6. An injection molded article according to claim 1 wherein said
pigment is in the form of a pigment concentrate.
7. An injection molded article according to claim 1, wherein said
masterbatch comprises a concentrate of carbon black in said
demoulding agent and said demoulding agent is pentaerythritol
tetrastearate.
8. The injection molded article according to claim 1, wherein the
coloured .[.polymer composition is a.]. polycarbonate composition
.[.comprising.]. .Iadd.comprises: .Iaddend. a) from 50 to 75 wt. %
of at least one thermoplastic polymer (a), b) from 0.1 to 1.5 wt. %
of at least one pigment component (b), c) from 0.1 to 1.5 wt. % of
at least one demoulding agent (c), d) from 20 to 60 wt. % of one or
more thermoplastic polyesters (d), e) from 2 to 20 wt. % of one or
more elastomers (e) other than component f, f) from 3 to 40 wt. %
of one or more optionally rubber-modified vinyl (co)polymers (f),
and g) from 0.2 to 10 wt. % one or more further additives.
9. The injection molded article according to claim 8, wherein the
demoulding agent is pentaerythritol tetrastearate.
10. An injection molded article according to claim 1, wherein the
demoulding agent is pentaerythitol tetrastearate.
11. An injection molded article according to claim 1, wherein the
masterbatch .[.is used in the form of.]. .Iadd.comprises
.Iaddend.granules or pellets of 1 to 5 mm in length.
12. An injection molded article according to claim 1, wherein the
masterbatch .[.is used in the form of.]. .Iadd.comprises
.Iaddend.powder having a diameter of 0.1 to 0.5 mm.
13. An injection molded article according to claim 1, wherein the
pigment .[.is used.]. in .[.the preparation of.]. the coloured
polymer composition .Iadd.is provided .Iaddend.solely in the form
of the masterbatch consisting of pigment and demoulding agent.
Description
CROSS REFERENCE TO RELATED APPLICATION
This .[.application.]. .Iadd.Application is a reissue of U.S.
application Ser. No. 13/332,047, filed on Dec. 20, 2011, issued as
U.S. Pat. No. 9,056,957, which .Iaddend.claims priority to European
Patent Application No. 10196932.7, filed Dec. 23, 2010, the content
of .Iadd.each of .Iaddend.which is incorporated herein by reference
in its entirety.
BACKGROUND
1. Field of the Invention
The invention provides pigment-containing polycarbonate compounds
having improved dispersion of the pigment particles in the polymer
matrix, and a process for the preparation of these compounds.
Carbon black is preferably used as the pigment, "carbon black" in
the present invention representing all particulate pure carbon
substrates and carbon compounds, for example colour carbon blacks,
conductivity carbon blacks, carbon nanotubes, graphite. The
pigment-containing polycarbonate compounds can contain further
polymers, such as, for example, elastomers or graft polymers, or
further thermoplastics, such as, for example, polyesters.
The present invention relates further to the use of pigment
masterbatches containing the pigment and a demoulding agent which
is to be added to the polycarbonate composition.
The present invention relates further to a process for the
preparation of such polycarbonate compounds having improved
dispersion of the pigment particles in the polymer matrix, in
which, in the compounding of the polycarbonate composition, a
masterbatch of the pigment in fatty acid esters based on aliphatic
alcohols or polyols is used. The invention further provides the
preparation of such pigment masterbatches in fatty acid esters.
2. Description of Related Art
A technical problem when incorporating pigments, and carbon black
particles in particular, into thermoplastic polymer compositions is
that of dispersing the pigment particles completely and uniformly
in the polymer matrix. Incompletely dispersed pigment particles
form pigment agglomerates which apart from colour inhomogeneities
and inadequate depth of colour also result in particular in defects
which have an adverse effect on the mechanical properties of the
polymer compositions, such as their strength and ultimate
elongation, and also on the surface properties of the materials.
Larger pigment agglomerates lead, for example, to faults and
defects on the surface of such compositions such as pitting,
streakiness and, ultimately, to an undesirable reduction in the
degree of gloss. In a composite with other materials, such surface
defects can additionally also adversely affect the composite
adhesion properties (for example lacquer adhesion).
Carbon-based pigments--such as, for example, carbon blacks,
graphites, fullerenes, graphenes, activated charcoals and carbon
nanotubes, which are used in many commercial fields of application,
for example for black colouration, for increasing the electrical or
thermal conductivity of the composition, for mechanical
strengthening or also for binding and reducing the volatility of
low molecular weight organic compounds such as residual monomers or
odour-bearing substances are distinguished by particularly strong
interparticle binding forces and therefore have a particularly high
tendency to form agglomerates, which can be broken up again only
with difficulty on incorporation into thermoplastic polymers.
Various methods are known from the prior art for improving the
dispersion of such pigments in thermoplastic polymer compositions.
For example, pigment dispersion can be improved by increasing the
specific energy input by means of shear during the incorporation of
the pigments into the polymer melt in conventional compounding
units such as twin-screw extruders or internal kneaders.
However, the energy input which can be used for pigment dispersion
is technically limited in the case of polymer melts, in particular
those having a low viscosity, that is to say high melt flowability,
as is required for good thermoplastic processability in most fields
of application. In other cases, the energy input is limited by the
thermal loading capacity of the polymer melt into which the pigment
is to be incorporated. High specific energy inputs naturally lead
to high process temperatures which, depending on the polymer, can
lead to undesirable damage, ageing or even decomposition of the
polymer.
A further method is the use of a highly concentrated masterbatch of
the pigment in a polymer matrix, but the technically achievable
concentration of the pigment in the polymer matrix is not high
enough for an economic application without the use of further
additives/processing aids. Furthermore, good pigment dispersion in
the end product can be achieved with this method only if the
pigments are already well dispersed in the masterbatch, which is
only insufficiently ensured when using polymer matrices, in
particular in polycarbonate.
A further possibility for improving the dispersion of pigments
consists in using dispersing aids, which reduce the intermolecular
interactions between the individual pigment particles or pigment
aggregates within a pigment agglomerate and thereby facilitate the
breaking up of the agglomerates during the preparation of the
compounds. The disadvantage of the use of such dispersing aids,
which have no other necessary action in the composition, is that
they remain in the polymer composition that is produced and, as a
result, may possibly adversely affect the application-related
properties of the target products.
For example, such dispersing aids in multiphase compositions
(blends) of different polymers (such as, for example,
impact-modified polymers) can adversely affect the phase
compatibility of the different polymer components by accumulating
at the phase boundaries and thereby adversely affect the mechanical
properties of the blend composition. Likewise, these additives can
catalyse undesirable ageing processes in certain polymer systems,
for example hydrolytic decomposition reactions in polycondensation
polymers.
The preparation of pigment concentrates in wax-like compounds is
already known from U.S. Pat. No. 4,484,952, wherein the preparation
of carbon black concentrates in PETS (pentaerythritol
tetrastearate) is also described. However, the shear forces which
occur under the stirring, spraying or centrifugation conditions
mentioned in U.S. Pat. No. 4,484,952 for mixing the pigments with
the carrier are too small to achieve sufficiently fine separation
and uniform distribution of the pigments in the carrier material in
the case of highly agglomerated pigments. However, this is a
necessary requirement for subsequent uniform dispersion of the
pigments in a polymer matrix with the aid of such pigment
concentrates. Moreover, U.S. Pat. No. 4,484,952 gives no indication
of the quality of the pigment dispersion which can be achieved in
thermoplastics with carbon black concentrates so prepared, in
particular the dispersion of the carbon black which can be achieved
in polycarbonate compositions. Furthermore, there is no information
in U.S. Pat. No. 4,484,952 regarding the process parameters used in
the preparation of the pigment concentrates and the energy input as
well as the mixing unit used, which have a critical influence on
the quality of the dispersion.
The preparation of pigment and, in particular, carbon black
concentrates in wax-like compounds is also known from U.S. Pat. No.
4,310,483. However, this is likewise a concentrate form in which
only a low energy input for the separation of agglomerated pigments
and their uniform distribution in the matrix material occurs. The
preparation process is in fact aimed at improving the metering
properties of the described pigment concentrates, dust formation
being largely avoided and a more advantageous metering form being
achieved by wetting of the pigments. The amount of pigment in the
described carbon black concentrates far exceeds the amount of
granulating aid used. Regarding the quality of the pigment
dispersion in thermoplastics using such pigment concentrates, it is
stated in U.S. Pat. No. 4,310,483 that it is equally as good as in
the case of the metering of pure powder without the use of
granulating aids, but an improvement in the dispersion is not
described.
WO 2002/092702 relates to the coating of carbon black pellets by
spraying with wax-like compounds, accordingly, for example, also
with PETS, in order to improve the metering properties of carbon
black products by the coating.
The preparation of carbon black-containing polycarbonate moulding
compositions using carbon black masterbatches is described in EP
578 245 A2. However, the masterbatches here are masterbatches in
polyethylenes. Polyethylenes lead to disadvantageous property
changes in polycarbonate moulding compositions, for example in
respect of the low-temperature strength of the moulding
compositions, and are therefore to be avoided.
US 2009/0057621 A1 describes the melt-mixing of carbon-containing
thermoplastic masterbatches with thermoplastics without isolation
of the masterbatch but with simultaneous continuous metering into a
second thermoplastic melt, wherein the thermoplastic can also be
polycarbonate. Such a process is technically too complex and
inflexible, however.
SUMMARY
In order to overcome disadvantages associated with the
above-mentioned art, it was, therefore, an object of the present
invention to provide a novel process for improved dispersion of
pigments, in particular carbon black, in polycarbonate
compounds.
In addition, when using pigment concentrates, no foreign substances
that do not have a necessary action in the composition are to be
introduced into the polycarbonate compounds.
Furthermore, a pigment concentrate in isolated form is to be
provided, which concentrate is suitable for incorporation into and
for the preparation of polycarbonate compounds having improved
pigment dispersion.
It was a further object of the invention, by the use of a pigment
concentrate, to achieve better dispersion of pigments in a polymer
matrix than is possible by metering the pure pigment in powder form
in a single compounding step, it still being possible to carry out
the preparation process under standard conditions in conventional
mixing units such as, for example, in single- or multi-shaft
extruders, kneaders or internal mixers.
Surprisingly, it has been found that pigments, in particular carbon
blacks, in substances which are used as demoulding agents for
polycarbonate moulding compositions, in a preferred embodiment in
aliphatic fatty acid esters, can, under defined conditions, be both
homogenously distributed and very well dispersed in the melt of the
fatty acid esters using mechanical shear, and that a carbon black
concentrate so prepared, after cooling, can be formed into pellets
and used in a subsequent compounding process as a masterbatch for
colouring thermoplastic compositions, in particular also for
colouring polycarbonate compositions. In principle, various types
of demoulding agents and various, in particular carbon-containing,
pigments are suitable for the preparation of such
masterbatches.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a structure of a co-kneader.
FIG. 2 shows a structure of a co-kneader without a retaining
ring.
FIG. 3 shows a structure of a co-kneader with a metering
hopper.
FIG. 4 shows a structure of an extruder with a length-to-diameter
ratio of 44.
FIG. 5 shows a structure of an extruder with a length-to-diameter
ratio of 36.
FIG. 6 shows a structure of an extruder with an injection
valve.
FIG. 7 shows a structure of an extruder with a length-to-diameter
ratio of 48.
FIG. 8 shows a structure of an extruder with a length-to-diameter
ratio of 31.5.
FIG. 9 shows a structure of an extruder with a length-to-diameter
ratio of 40.
FIG. 10 shows a graph.
FIG. 11 shows a diagram of the process parameters of an extruder
denoting notched impact strength at an ambient temperatures of
260.degree. C.
FIG. 12 shows a diagram of the process parameters of an extruder
denoting notched impact strength at an ambient temperatures of
300.degree. C.
DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT
Objects of the present invention can be achieved, for example, by
the compositions, the process and the use as disclosed hereinbelow
and described in the claims, the preferred embodiments according to
the invention generally being described hereinbelow with carbon
black as the preferred pigment by way of example, but this does not
imply any fundamental limitation to carbon black as the
pigment.
Concentrates of suitable carbon black types in demoulding agents
containing fatty acid esters were prepared, which concentrates can
preferably be granulated at room temperature. The demoulding agent
that is preferably used for the preparation of such carbon black
masterbatches is pentaerythritol tetrastearate (PETS). However,
other fatty acid esters, preferably those which are solid at room
temperature (20.degree. C.), can likewise be used for the
preparation of carbon black masterbatches according to the
invention. The carbon black masterbatches according to the
invention can be prepared in conventional compounding units in the
melt of the fatty acid esters with the application of sufficiently
high shear energy for the adequate separation of any agglomerated
carbon black particles.
It has further been found that polycarbonate moulding compositions
which have been prepared and coloured using the carbon black
masterbatches according to the invention by compounding in a single
compounding step in conventional mixing units such as, for example,
single- or multi-shaft extruders, kneaders or internal mixers under
standard conditions, exhibit substantially improved dispersion of
the carbon black particles in the polycarbonate matrix after
thermoplastic processing to moulded articles. The polycarbonate
moulding compositions can contain further thermoplastics or
particulate elastomeric polymers, as well as conventional fillers
and polymer additives.
Accordingly, the invention provides, in particular, a process for
the preparation of carbon black-containing polycarbonate moulding
compositions, wherein the carbon black is present in finely
dispersed form in the form of a masterbatch in a substance which is
used as demoulding agent in the formulation of the polycarbonate
moulding compositions and accordingly exhibits a necessary action
in the composition, and is introduced into the polycarbonate
moulding composition by melt compounding. The carbon black
masterbatch is preferably in the form of a pellet, as described
above, and is used and metered as such in the compounding process.
As an alternative, however, such a carbon black masterbatch,
because of the low melt viscosity at the relatively low melting
points, can also be fed into the compounding unit in liquid or
pasty form with the aid of melt metering pumps.
Suitable mixing units for the preparation of the carbon black
masterbatch are single- or multi-shaft extruders or kneaders, such
as, for example, Buss co-kneaders or internal mixers or shear
rollers, and any mixing units with which a sufficiently high shear
energy can be introduced into the melt of carbon black and
demoulding agent in order to finely separate any solid carbon black
agglomerates and distribute them uniformly in the demoulding
agent.
The starting components carbon black and demoulding agent are fed
to the compounding unit either separately or in the form of a
powder or grain or granule mixture and are intimately mixed in the
melt at a heating temperature of the housing of from 25.degree. C.
to 200.degree. C., preferably from 30.degree. C. to 130.degree.
C.
The masterbatches so obtained, depending on their carbon black
content and the demoulding agent used, preferably have a solid
consistency at room temperature. For metering in the form of a
solid, the carbon black masterbatches are formed into melt strands,
optionally filtered in the melt through a fine-mesh sieve (10-100
.mu.m mesh size, preferably 20-50 .mu.m) in order to retain
incompletely separated carbon black agglomerates, and then cooled
to temperatures below 40.degree. C., preferably below 30.degree.
C., and subsequently granulated.
Suitable granulating devices for the preparation of sufficiently
finely divided granules/pellets of the carbon black masterbatch
which can readily be metered in the subsequent compounding of the
polycarbonate moulding compositions are underwater or hot-face
water-ring granulators. The granules or pellets so obtained have a
maximum length of preferably 8 mm, particularly preferably not more
than 5 mm, and a minimum length of preferably 0.5 mm, particularly
preferably not less than 1 mm, the length defining the axis in the
direction of the greatest extent of a body.
In an alternative embodiment, the masterbatch is used in the form
of a powder having a maximum diameter smaller than 0.5 mm and not
less than 0.1 mm.
The amount of carbon black or pigment in the masterbatch can vary
within relatively wide limits from 3 wt. % to 70 wt. %, based on
the masterbatch; the carbon black content is preferably from wt. %
to 70 wt. %, more preferably from 35 wt. % to 65 wt. %,
particularly preferably from 40 to 60 wt. %.
The nature of the pigment used and in particular also of the carbon
black used can vary very greatly, the term "carbon black" also
including chemical species such as carbon nanotubes, graphite,
conductivity carbon black and colour carbon black, as well as
carbon blacks obtained by very different production processes.
Colour carbon blacks and conductivity carbon blacks are
particularly preferred, and colour carbon blacks are most
particularly preferred. These carbon blacks can optionally also be
used together with other organic or inorganic pigments either in
the carbon black masterbatch or in the compounding of the
polycarbonate moulding composition. Carbon nanotubes (CNTs) are
preferably not used in an alternative embodiment.
The nature of the demoulding agent used can likewise vary greatly,
there preferably being used compounds such as low molecular weight
polyolefin oils or waxes, hydrogenated oils, montanic acid or fatty
acid esters, which preferably have a solid consistency at room
temperature. Further preferred demoulding agents are aliphatic
montanic or fatty acid esters, such as, for example, glycerol
stearates or palmitates or pentaerythritol stearates.
Pentaerythritol tetrastearate (PETS) is particularly preferred.
These carbon black masterbatches prepared according to the
invention are intimately mixed with polymers, preferably with
polycarbonate and optionally further components of the polymer,
preferably polycarbonate, moulding composition in conventional
melt-mixing units, such as, for example, in single- or multi-shaft
extruders or in kneaders, in the melt under conventional
conditions, and the mixture is extruded and granulated. They can be
metered at a suitable location into the solids feed region of the
extruder or into the polymer melt, either separately in the form of
granules or pellets via proportioning weighers or lateral feed
devices or alternatively at elevated temperature in the form of a
melt by means of metering pumps. The masterbatches in the form of
granules or pellets can also be combined with other particulate
compounds to give a premixture and then fed together into the
solids feed region of the extruder or into the polymer melt in the
extruder via metering hoppers or lateral feed devices. The
compounding unit is preferably a twin-shaft extruder, particularly
preferably a twin-shaft extruder having co-rotating shafts, the
twin-shaft extruder having a length/diameter ratio of the screw
shaft of preferably from 20 to 44, particularly preferably from 28
to 40. Such a twin-shaft extruder comprises a melting and mixing
zone or a combined melting and mixing zone (this "melting and
mixing zone" is also referred to hereinbelow as the "kneading and
melting zone") and optionally a degassing zone in which an absolute
pressure p.sub.abs of preferably not more than 800 mbar, more
preferably not more than 500 mbar, particularly preferably not more
than 200 mbar, is set. The mean residence time of the mixture
composition in the extruder is preferably limited to not more than
120 s, particularly preferably not more than 80 s, particularly
preferably not more than 60 s. In a preferred embodiment, the
temperature of the melt of the polymer or of the polymer alloy at
the extruder outlet is from 200.degree. C. to 400.degree. C.
The invention accordingly also provides pigment-containing polymer
moulding compositions, in a preferred embodiment polycarbonate
moulding compositions, having improved pigment dispersion, which
moulding compositions are prepared by the process according to the
invention, that is to say using a pigment-demoulding agent
concentrate according to the invention containing a) from 1 to
99.96 wt. %, preferably from 40 to 99.9 wt. %, more preferably from
50 to 99.8 wt. %, particularly preferably from 50 to 75 wt. %, of
at least one thermoplastic polymer (a), b) from 0.02 to 10 wt. %,
preferably from 0.05 to 5 wt. %, more preferably from 0.1 to 3 wt.
%, particularly preferably from 0.1 to 1.5 wt. %, of at least one
pigment component (b), in a preferred embodiment of a carbon-based
pigment, in a particularly preferred embodiment carbon black, c)
from 0.02 to 10 wt. %, preferably from 0.05 to 5 wt. %, more
preferably from 0.1 to 3 wt. %, particularly preferably from 0.1 to
1.5 wt. %, of at least one demoulding agent (c), d) from 0 to 70
wt. %, preferably from 0 to 60 wt. %, more preferably from 2 to 60
wt. %, particularly preferably from 20 to 60 wt. %, of one or more
thermoplastic polyesters (d), e) from 0 to 50 wt. %, preferably
from 0 to 40 wt. %, more preferably from 1 to 30 wt. %,
particularly preferably from 2 to 20 wt. %, of one or more
elastomers (e) other than component f) from 0 to 70 wt. %,
preferably from 0 to 60 wt. %, more preferably from 1 to 50 wt. %,
particularly preferably from 3 to 40 wt. %, of one or more
optionally rubber-modified vinyl (co)polymers (f), and g) from 0 to
40 wt. %, preferably from 0 to 30 wt. %, more preferably from 0.1
to 20 wt. %, particularly preferably from 0.2 to 10 wt. %, of
further additives.
Components b and c can be used in the preparation of the
pigment-containing polymer moulding compositions according to the
invention either wholly or only partially in the form of a
masterbatch of components b and c. In a preferred embodiment,
carbon-based pigments according to component b are used in the
preparation of the pigment-containing polymer moulding compositions
according to the invention solely in the form of a masterbatch of
components b and c, it being possible, however, for a portion of
component c in this preferred embodiment also to be used in the
form of the pure component in the preparation of the
pigment-containing polymer moulding compositions according to the
invention. In a particularly preferred embodiment, components b and
c are used in the preparation of the pigment-containing polymer
moulding compositions according to the invention solely in the form
of a masterbatch of components b and c.
Moulded articles which have been produced by thermoplastic
processing, for example by injection moulding, from these
pigment/carbon black-containing polymer/polycarbonate moulding
compositions prepared according to the invention exhibit a markedly
more homogeneous moulding surface with markedly fewer optical
imperfections, that is to say surface defects, and markedly
improved strength, in particular improved notched impact strength,
as compared with polymer/polycarbonate moulding compositions of the
same composition which have been prepared by direct compounding,
for example from powder mixtures or by compounding using
thermoplastic-based pigment/carbon black masterbatches.
In a preferred embodiment, the number of surface defects (pitting,
craters, pinholes, etc.) on moulded articles produced by the
injection moulding process from the polymer/polycarbonate
compositions according to the invention is reduced by at least 20%,
particularly preferably by 20 to 95 percent, as compared with
moulded articles of the moulding compositions having the same
composition which have been prepared by a different process, in
particular by a one-step compounding process using pigment
component b in powder form.
The surface defects of injection-moulded articles produced on
injection moulding tools with a high-gloss finish (ISO N1) can be
identified and quantified by optical analysis methods, all
imperfections having a mean diameter of at least 10 min being used
in determining the number of surface defects. The number of surface
defects was determined by observing the moulding surfaces under a
reflected light microscope--e.g. Zeiss Axioplan 2
motorised--through an object lens with 2.5.times. magnification in
a bright field, with illumination by means of a halogen 100 light
source. The number of defects in a surface region measuring 4
cm.times.4 cm was determined by scanning the area in a meandering
manner. The determination was assisted by a camera--e.g. Axiocam
IRC--with image evaluation software--e.g. KS 300 Zeiss.
According to analysis by Raman spectroscopy, the surface defects
thus determined optically on mouldings of polymer/polycarbonate
moulding compositions having the above-mentioned compositions
represent agglomerates and aggregates of pigments, in particular
carbon black particles, optionally together with elastomer
particles of components E and/or F, which are inadequately
separated in the melt compounding of the components in the
extruder. Such surface defects are clearly visible by reflected
light microscopy of suitable sections of the material samples. Such
surface defects usually have mean diameters of from about 10 .mu.m
to about 300 .mu.m.
In the preparation according to the invention of the pigment/carbon
black-containing polymer/polycarbonate moulding compositions,
further process-related measures can be taken which further assist
in improving the dispersion of the pigment/carbon black in the
polymer matrix. For example, during the compounding of the
pigment/carbon black-containing polymer/polycarbonate moulding
compositions in the melt, water can be added in amounts of from 0.2
to 10 wt. %, based on the moulding composition, and removed again
via a degassing nozzle of the extruder, as described in DE 10 2009
009680 and EP 10001490.1. Likewise, compounding of the
pigment/carbon black-containing polymer/polycarbonate moulding
compositions can be carried out on extruders having enlarged gap
widths between the screw crest and the housing wall, as described
in EP 1016954.7. All these measures bring about improvements in the
dispersion of the pigment/carbon black in the polymer/polycarbonate
moulding compositions both on their own and in combination with one
another.
Component a
There can be used as thermoplastic polymers a in the compositions
according to the invention, for example, polyolefins (such as
polyethylene and polypropylene), vinyl (co)polymers such as
polyvinyl chloride, styrene (co)polymers (e.g.
styrene-acrylonitrile copolymers, acrylonitrile-butadiene-styrene
copolymers, polyacrylates, polyacrylonitrile), polyvinyl acetate,
thermoplastic polyurethanes, polyacetals (such as polyoxymethylene
and polyphenylene ether), polyamides, polyimides, polycarbonates,
polyesters, polyester carbonates, polysulfones, polyarylates,
polyaryl ethers, polyphenylene ethers, polyarylsulfones, polyaryl
sulfides, polyether sulfones, polyphenylene sulfide, polyether
ketones, polyamide imides, polyether imides and polyester
imides.
In a preferred embodiment there is used as the thermoplastic
polymer a in the compositions according to the invention at least
one representative selected from the group of the aromatic
polycarbonates and aromatic polyester carbonates.
Aromatic polycarbonates and/or aromatic polyester carbonates
according to component a that are suitable according to the
invention are known in the literature or can be prepared by
processes known in the literature (for the preparation of aromatic
polycarbonates see, for example, Schnell, "Chemistry and Physics of
Polycarbonates", Interscience Publishers, 1964 and DE-AS 1 495 626,
DE-A 2 232 877, BE-A 2 703 376, DE-A 2 714 544, DE-A 3 000 610,
DE-A 3 832 396; for the preparation of aromatic polyester
carbonates see e.g. BE-A 3 007 934). The preparation of aromatic
polycarbonates is carried out, for example, by reaction of
diphenols with carbonic acid halides, preferably phosgene, and/or
with aromatic dicarboxylic acid dihalides, preferably
benzenedicarboxylic acid dihalides, according to the interfacial
process, optionally using chain terminators, for example
monophenols, and optionally using branching agents having a
functionality of three or more than three, for example triphenols
or tetraphenols. Preparation by a melt polymerisation process by
reaction of diphenols with, for example, diphenyl carbonate is also
possible.
Diphenols for the preparation of the aromatic polycarbonates and/or
aromatic polyester carbonates are preferably those of formula
(I)
##STR00001## wherein A is a single bond, C.sub.1- to
C.sub.5-alkylene, C.sub.2- to C.sub.5-alkylidene, C.sub.5- to
C.sub.6-cycloalkylidene, --O--, --SO--, --CO--, --S--,
--SO.sub.2--, C.sub.6- to C.sub.12-arylene, to which further
aromatic rings optionally containing heteroatoms can be fused,
or a radical of formula (II) or (III)
##STR00002## B is in each case C.sub.1- to C.sub.12-alkyl,
preferably methyl, halogen, preferably chlorine and/or bromine, x
each independently of the other is 0, 1 or 2, p is 1 or 0, and
R.sup.5 and R.sup.6 can be chosen individually for each X.sup.1 and
each independently of the other is hydrogen or C.sub.1- to
C.sub.6-alkyl, preferably hydrogen, methyl or ethyl, X.sup.1 is
carbon and m is an integer from 4 to 7, preferably 4 or 5, with the
proviso that on at least one atom X.sup.1, R.sup.5 and R.sup.6 are
simultaneously alkyl.
Preferred diphenols are hydroquinone, resorcinol,
dihydroxydiphenols, bis-(hydroxyphenyl)-C.sub.1-C.sub.5-alkanes,
bis-(hydroxyphenyl)-C.sub.5-C.sub.6-cycloalkanes,
bis-(hydroxyphenyl) ethers, bis-(hydroxy-phenyl) sulfoxides,
bis-(hydroxyphenyl) ketones, bis-(hydroxyphenyl)-sulfones and
.alpha.,.alpha.-bis-(hydroxyphenyl)-diisopropyl-benzenes, and
derivatives thereof brominated and/or chlorinated on the ring.
Particularly preferred diphenols are 4,4'-dihydroxydiphenyl,
bisphenol A, 2,4-bis(4-hydroxy-phenyl)-2-methylbutane,
1,1-bis-(4-hydroxyphenyl)-cyclohexane,
1,1-bis-(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane,
4,4'-dihydroxydiphenyl sulfide, 4,4'-dihydroxydiphenylsulfone and
di- and tetra-brominated or chlorinated derivatives thereof, such
as, for example, 2,2-bis(3-chloro-4-hydroxyphenyl)-propane,
2,2-bis-(3,5-dichloro-4-hydroxyphenyl)-propane or
2,2-bis-(3,5-dibromo-4-hydroxyphenyl)-propane.
2,2-Bis-(4-hydroxyphenyl)-propane (bisphenol A) is particularly
preferred.
The diphenols can be used on their own or in the form of arbitrary
mixtures. The diphenols are known in the literature or are
obtainable according to processes known in the literature.
Chain terminators suitable for the preparation of thermoplastic
aromatic polycarbonates are, for example, phenol, p-chlorophenol,
p-tert-butylphenol or 2,4,6-tribromophenol, but also long-chained
alkylphenols, such as 4-[2-(2,4,4-trimethylpentyl]-phenol,
4-(1,3-tetramethylbutyl)-phenol according to DE-A 2 842 005 or
monoalkylphenol or dialkylphenols having a total of from 8 to 20
carbon atoms in the alkyl substituents, such as
3,5-di-tert-butylphenol, p-isooctylphenol, p-tert-octylphenol,
p-dodecylphenol and 2-(3,5-dimethylheptyl)-phenol and
4-(3,5-dimethylheptyl)-phenol. The amount of chain terminators to
be used is generally from 0.5 mol % to 10 mol %, based on the molar
sum of the diphenols used in a particular case.
The thermoplastic aromatic polycarbonates have mean weight-average
molecular weights (M.sub.w, measured by GPC (gel permeation
chromatography with polycarbonate standard in dichloromethane) of
from 10,000 to 200,000 g/mol, preferably from 15,000 to 80,000
g/mol, particularly preferably from 24,000 to 32,000 g/mol.
The thermoplastic aromatic polycarbonates can be branched in a
known manner, preferably by the incorporation of from 0.05 to 2.0
mol %, based on the sum of the diphenols used, of compounds having
a functionality of three or more than three, for example those
having three or more phenolic groups. Preference is given to linear
polycarbonates, more preferably based on bisphenol A.
Both homopolycarbonates and copolycarbonates are suitable. For the
preparation of copolycarbonates of component a according to the
invention it is also possible to use from 1 to 25 wt. %, preferably
from 2.5 to 25 wt. %, based on the total amount of diphenols to be
used, of polydiorganosiloxanes having hydroxyaryloxy end groups.
These are known (U.S. Pat. No. 3,419,634) and can be prepared
according to processes known in the literature.
Polydiorganosiloxane-containing copolycarbonates are likewise
suitable; the preparation of copolycarbonates containing
polydiorganosiloxanes is described, for example, in DE-A 3 334
782.
Preferred polycarbonates in addition to the bisphenol A
homopolycarbonates are the copolycarbonates of bisphenol A with up
to 15 mol %, based on the molar sums of diphenols, of diphenols
other than those mentioned as being preferred or particularly
preferred, in particular
2,2-bis(3,5-dibromo-4-hydroxyphenyl)-propane.
Aromatic dicarboxylic acid dihalides for the preparation of
aromatic polyester carbonates are preferably the diacid dichlorides
of isophthalic acid, terephthalic acid, diphenyl ether
4,4'-dicarboxylic acid and naphthalene-2,6-dicarboxylic acid.
Mixtures of the diacid dichlorides of isophthalic acid and
terephthalic acid in a ratio of from 1:20 to 20:1 are particularly
preferred.
In the preparation of polyester carbonates, a carbonic acid halide,
preferably phosgene, is additionally used concomitantly as
bifunctional acid derivative.
Suitable chain terminators for the preparation of the aromatic
polyester carbonates, in addition to the monophenols already
mentioned, are also the chlorocarbonic acid esters thereof and the
acid chlorides of aromatic monocarboxylic acids, which can
optionally be substituted by C.sub.1- to C.sub.22-alkyl groups or
by halogen atoms, as well as aliphatic C.sub.2- to
C.sub.22-monocarboxylic acid chlorides.
The amount of chain terminators is in each case from 0.1 to 10 mol
%, based in the case of phenolic chain terminators on moles of
diphenol and in the case of monocarboxylic acid chloride chain
terminators on moles of dicarboxylic acid dichloride.
In the preparation of aromatic polyester carbonates, one or more
aromatic hydroxycarboxylic acids can additionally be used.
The aromatic polyester carbonates can be both linear and branched
in known manner (see in this connection DE-A 2 940 024 and DE-A 3
007 934), linear polyester carbonates being preferred.
There can be used as branching agents, for example, carboxylic acid
chlorides, such as trimesic acid trichloride, cyanuric acid
trichloride, 3,3'-,4,4'-benzophenone-tetracarboxylic acid
tetrachloride, 1,4,5,8-naphthalenetetracarboxylic acid
tetrachloride or pyromellitic acid tetrachloride, in amounts of
from 0.01 to 1.0 mol % (based on dicarboxylic acid dichlorides
used), or phenols having a functionality of three or more, such as
phloroglucinol,
4,6-dimethyl-2,4,6-tri-(4-hydroxyphenyl)-hept-2-ene,
4,6-dimethyl-2,4,6-tri-(4-hydroxyphenyl)-heptane,
1,3,5-tri-(4-hydroxyphenyl)-benzene,
1,1,1-tri-(4-hydroxyphenyl)-ethane,
tri-(4-hydroxyphenyl)-phenylmethane,
2,2-bis[4,4-bis(4-hydroxyphenyl)-cyclohexyl]-propane,
2,4-bis(4-hydroxyphenylisopropyl)-phenol,
tetra-(4-hydroxyphenyl)-methane,
2,6-bis(2-hydroxy-5-methyl-benzyl)-4-methyl-phenol,
2-(4-hydroxyphenyl)-2-(2,4-dihydroxyphenyl)-propane,
tetra-(4-[4-hydroxyphenyl-isopropyl]-phenoxy)-methane,
1,4-bis[4,4'-dihydroxytriphenyl)-methyl]-benzene, in amounts of
from 0.01 to 1.0 mol %, based on diphenols used. Phenolic branching
agents can be placed in a vessel with the diphenols; acid chloride
branching agents can be introduced together with the acid
dichlorides.
The content of carbonate structural units in the thermoplastic
aromatic polyester carbonates can vary as desired. The content of
carbonate groups is preferably up to 100 mol %, in particular up to
80 mol %, particularly preferably up to 50 mol %, based on the sum
of ester groups and carbonate groups. Both the esters and the
carbonates contained in the aromatic polyester carbonates can be
present in the polycondensation product in the form of blocks or
distributed randomly.
The thermoplastic aromatic polycarbonates and polyester carbonates
can be used on their own or in an arbitrary mixture.
Components a which are particularly preferably used according to
the invention are polycarbonates, with bisphenol A
homopolycarbonates being particularly preferred.
Component b
There are used as component b in principle any desired inorganic or
organic, natural or synthetically prepared pigments. A pigment is
understood as being a colour-giving substance which is insoluble in
the application medium (here the thermoplastic polymer according to
component a). Examples of such pigments are titanium dioxide,
carbon black, bismuth pigments, metal oxides, metal hydroxides,
metal sulfides, iron cyan blue, ultramarine, cadmium pigments,
chromate pigments, azo pigments as well as polycyclic pigments.
There are preferably used as component b those pigments which have
strong interparticle binding forces (van der Waals forces), because
these are particularly difficult to disperse.
Component b is particularly preferably at least one carbon-based
pigment selected from the group consisting of carbon black,
graphite, fullerene, graphene, activated charcoal and carbon
nanotubes (CNTs).
There are suitable as carbon nanotubes both those having a
single-layer wall (single-walled carbon nanotubes=SWCNTs) and those
having a multi-layer wall (multi-walled carbon
nanotubes=MWCNTs).
Carbon nanotubes (CNTs) are preferably understood as being
cylindrical carbon tubes having a carbon content of >95%, which
tubes do not contain any amorphous carbon. The carbon nanotubes
preferably have an outside diameter of from 3 to 80 nm,
particularly preferably from 5 to 20 nm. The mean value of the
outside diameter is preferably from 13 to 16 nm. The length of the
cylindrical carbon nanotubes is preferably from 0.1 to 20 .mu.m,
particularly preferably from 1 to 10 .mu.m. The carbon nanotubes
preferably consist of from 2 to 50, particularly preferably from 3
to 15, graphitic layers (also referred to as "walls"), which have a
smallest inside diameter of from 2 to 6 nm. These carbon nanotubes
are also referred to as "carbon fibrils" or "hollow carbon fibres",
for example.
The production of the CNTs used according to the invention is
generally known (see e.g. U.S. Pat. No. 5,643,502 and DE-A 10 2006
017 695); they are preferably produced by the process disclosed in
DE-A 10 2006 017 695, particularly preferably by the process
disclosed in Example 3 of DE-A 10 2006 017 695.
In an alternative embodiment, carbon-based pigments according to
component b are preferably not used in the form of carbon
nanotubes, but carbon-based pigments with the exception of CNTs,
preferably carbon black, particularly preferably colour carbon
black, are employed as component b.
Carbon black is a black pulverulent solid which, depending on the
quality and use, consists substantially of carbon. The carbon
content of carbon black is generally from 80.0 to 99.9 wt. %. In
the case of carbon blacks which have not been subjected to
oxidative after-treatment, the carbon content is preferably from
96.0 to 95.5 wt. %. By extraction of the carbon black with organic
solvents, for example with toluene, traces of organic impurities on
the carbon black can be removed and the carbon content can thereby
be increased to more than 99.9 wt. %. In the case of carbon blacks
which have undergone oxidative after-treatment, the oxygen content
can be up to 30 wt. %, preferably up to wt. %, in particular from 5
to 15 wt. %.
Carbon black consists of mostly spherical primary particles having
a size of preferably from 10 to 500 nm. These primary particles
have grown together to form chain-like or branched aggregates. The
aggregates are generally the smallest unit of the carbon black
which can be separated in a dispersing process. Many of these
aggregates in turn combine by intermolecular (van der Waals) forces
to form agglomerates. By varying the production conditions, both
the size of the primary particles and the aggregation (structure)
thereof can purposively be adjusted. The person skilled in the art
understands structure as being the type of three-dimensional
arrangement of the primary particles in an aggregate. A "high
structure" refers to carbon blacks with highly branched and
crosslinked aggregate structures; in the case of largely linear
aggregate structures, that is to say aggregate structures with
little branching and crosslinking, on the other hand, the term "low
structure" is used.
The oil adsorption number measured according to ISO 4656 with
dibutyl phthalate (DBP) is generally given as a measure of the
structure of a carbon black. A high oil absorption number is
indicative of a high structure.
The primary particle size of a carbon black can be determined, for
example, by means of scanning electron microscopy. However, the BET
surface area of the carbon black, determined according to ISO 4652
with nitrogen adsorption, is also used as a measure of the primary
particle size of a carbon black. A high BET surface area is
indicative of a small primary particle size.
The dispersibility of the agglomerates of a carbon black depends on
the primary particle size and the structure of the aggregates, the
dispersibility of the carbon black generally decreasing as the
primary particle size and the structure decrease.
As a commercial product, industrial carbon black is produced by
incomplete combustion or pyrolysis of hydrocarbons. Processes for
the production of industrial carbon black are known in the
literature. Known processes for the production of industrial carbon
blacks are in particular the furnace, gas black, flame black,
acetylene black and thermal black processes.
The particle size distribution of the primary particles and the
size and structure of the primary particle aggregates determine the
properties such as depth of colour, ground shade and conductivity
of the carbon black. Conductive carbon blacks generally have small
primary particles and highly branched aggregates. Colour carbon
blacks are generally carbon blacks with very small primary
particles and are often subjected to subsequent oxidation after
production by one of the above-mentioned processes. The oxidic
groups thereby attached to the carbon black surface are intended to
increase the compatibility with the resins into which the carbon
blacks are to be introduced and dispersed.
Colour carbon blacks are preferably used as component b. In a
preferred embodiment they have a mean primary particle size,
determined by scanning electron microscopy, of from 10 to 100 nm,
more preferably from 10 to 50 nm, particularly preferably from 10
to 30 nm, in particular from 10 to 20 nm. The particularly finely
divided colour carbon blacks are therefore particularly preferred
in the process according to the invention because the depth of
colour and UV resistance which can be achieved with a particular
amount of carbon black increases as the primary particle size
decreases but, on the other hand, their dispersibility also
decreases, for which reason such very finely divided carbon blacks
in particular are in need of improvement in respect of their
dispersibility.
The colour carbon blacks which are preferably used as component b
have a BET surface area, determined according to ISO 4652 by
nitrogen adsorption, of preferably at least 20 m.sup.2/g, more
preferably of at least 50 m.sup.2/g, particularly preferably of at
least 100 m.sup.2/g, in particular of at least 150 m.sup.2/g.
Colour carbon blacks which are preferably used as component b are
additionally characterised by an oil adsorption number, measured
according to ISO 4656 with dibutyl phthalate (DBP), of preferably
from 10 to 200 ml/100 g, more preferably from 30 to 150 ml/100 g,
particularly preferably from 40 to 120 ml/100 g, in particular from
40 to 80 ml/100 g. The colour carbon blacks with a low oil
adsorption number generally achieve a better depth of colour and
are preferred in that regard but, on the other hand, they are
generally more difficult to disperse, for which reason such carbon
blacks in particular are in need of improvement in respect of their
dispersibility.
The carbon blacks which are used as component b can and are
preferably used in pellet or pearl form. Pearl formation or
pelletisation is carried out by processes known in the literature
and serves on the one hand to increase the bulk density and improve
the metering (flow) properties but, on the other hand, is also
carried out for occupational health reasons. The pellets or pearls
are preferably so adjusted in terms of their hardness that they
withstand transport and feeding processes during metering largely
undamaged but break up into agglomerates again completely under the
action of high mechanical shear forces as occur, for example, in
conventional powder mixing devices and/or compounding units.
Component c
Demoulding agents which can be used according to the invention are
compounds having softening temperatures of preferably below
120.degree. C., particularly preferably from 20.degree. C. to
100.degree. C., most particularly preferably from 40.degree. C. to
80.degree. C., such as, for example, low molecular weight
polyolefin oils or waxes, montan waxes, aliphatic or aromatic
carboxylic acid esters based on fatty acids and/or fatty alcohols.
Demoulding agents which are preferred according to the invention
are aliphatic carboxylic acid esters. These are esters of aliphatic
long-chained carboxylic acids with mono- or di-valent aliphatic
and/or aromatic, preferably aliphatic, hydroxy compounds.
Aliphatic carboxylic acid esters which are particularly preferably
used are or contain compounds of the general formula (IV):
(R.sub.2--CO--O).sub.o--R.sub.3--(OH).sub.p where o=1 to 4 and p=0
to 3 (IV), wherein R.sub.2 is an aliphatic saturated or
unsaturated, linear, cyclic or branched alkyl radical and R.sub.3
is an alkylene radical of a mono- to tetra-hydric aliphatic alcohol
of the formula R.sub.3--(OH).sub.o+p. In the compounds of formula
(IV), the o radicals R.sub.2 in the same molecule can also have
different structures.
Particularly preferred for R.sub.2 are C.sub.1-C.sub.30-,
particularly preferably C.sub.4-C.sub.28-, most particularly
preferably C.sub.12-C.sub.24-alkyl radicals. C.sub.1-C.sub.30-Alkyl
represents, for example, methyl, ethyl, n-propyl, isopropyl,
n-butyl, sec-butyl, tert-butyl, n-pentyl, 1-methylbutyl,
2-methylbutyl, 3-methylbutyl, neopentyl, 1-ethylpropyl, cyclohexyl,
cyclopentyl, n-hexyl, 1,1-dimethylpropyl, 1,2-dimethylpropyl,
1,2-dimethylpropyl, 1-methylpentyl, 2-methylpropyl, 3-methylpentyl,
4-methylpentyl, 1,1-dimethylbutyl, 1,2-dimethylbutyl,
1,3-dimethylbutyl, 2,2-dimethylbutyl, 2,3-dimethylbutyl,
3,3-dimethylbutyl, 1-ethylbutyl, 2-ethylbutyl,
1,1,2-trimethylpropyl, 1,2,2-trimethylpropyl,
1-ethyl-1-methylpropyl, 1-ethyl-2-methylpropyl or
1-ethyl-2-methylpropyl, n-heptyl and n-octyl, pinacyl, adamantyl,
the isomeric menthyls, n-nonyl, n-decyl, n-dodecyl, n-tridecyl,
n-tetradecyl, n-hexadecyl or n-octadecyl.
Particularly preferred for R.sub.3 are C.sub.1-C.sub.30-,
particularly preferably C.sub.1-C.sub.18-alkylene radicals.
Alkylene represents a straight-chained, cyclic, branched or
unbranched alkylene radical. C.sub.1-C.sub.18-Alkylene represents,
for example, methylene, ethylene, n-propylene, isopropylene,
n-butylene, n-pentylene, n-hexylene, n-heptylene, n-octylene,
n-nonylene, n-decylene, n-dodecylene, n-tridecylene,
n-tetradecylene, n-hexadecylene or n-octadecylene.
In the case of esters of polyhydric alcohols, free, non-esterified
OH groups can also be present. Aliphatic carboxylic acid esters
which are suitable according to the invention are, for example and
preferably, glycerol monostearate (GMS), palmityl palmitate and
stearyl stearate. Mixtures of different carboxylic acid esters of
formula (IV) can also be used. Carboxylic acid esters which are
preferably used are additionally mono- or poly-esters of
pentaerythritol, glycerol, trimethylolpropane, propanediol, stearyl
alcohol, cetyl alcohol or myristyl alcohol with myristic, palmitic,
stearic or montanic acid and mixtures thereof. Pentaerythritol
tetrastearate, glycerol monostearate, stearyl stearate and
propanediol distearate, or mixtures thereof, are particularly
preferred.
A particularly preferred demoulding agent according to the
invention is pentaerythritol tetrastearate and glycerol
monostearate, in particular pentaerythritol tetrastearate.
Component d
Thermoplastic polyesters according to component d which can be used
according to the invention are polyalkylene terephthalates, which
can be prepared by methods known in the literature (see e.g.
Kunststoff-Handbuch, Volume VIII, p, 695 ff, Carl-Hanser-Verlag,
Munich 1973).
In a preferred embodiment, the polyalkylene terephthalates are
reaction products of aromatic dicarboxylic acids or reactive
derivatives thereof, such as dimethyl esters or anhydrides, and
aliphatic, cycloaliphatic or araliphatic diols, as well as mixtures
of these reaction products.
Particularly preferred polyalkylene terephthalates contain at least
80 wt. %, preferably at least 90 wt. %, based on the dicarboxylic
acid component, terephthalic acid radicals and at least 80 wt. %,
preferably at least 90 mol %, based on the diol component, ethylene
glycol and/or 1,4-butanediol radicals.
Particular preference is given to polyalkylene terephthalates which
have been prepared solely from terephthalic acid and reactive
derivatives thereof (e.g. dialkyl esters thereof) and ethylene
glycol and/or 1,4-butanediol, and mixtures of these polyalkylene
terephthalates. Polyalkylene terephthalates which are particularly
preferably used according to the invention are polybutylene
terephthalate (PBT) and polyethylene terephthalate (PET).
Component e
There can be used according to the invention as component e any
elastomers other than component f which have a glass transition
temperature <10.degree. C., preferably <0.degree. C.,
particularly preferably <-20.degree. C.
There are preferably used as component e, for example,
thermoplastic elastomers such as, for example, olefin-based
thermoplastic elastomers (TPO), polyurethane-based thermoplastic
elastomers (TPU), and thermoplastic styrene block copolymers
(TPS).
Unless expressly described otherwise in the present invention, the
glass transition temperature is determined for all components by
means of differential scanning calorimetry (DSC) according to DIN
EN 61006 at a heating rate of 10 K/min with determination of the Tg
as the mid-point temperature (tangent method).
Component f
Rubber-modified vinyl (co)polymers which can be used according to
the invention as component fare one or more graft polymers of f.1
from 5 to 95 wt. %, preferably from 10 to 90 wt. %, particularly
preferably from 30 to 60 wt. %, of at least one vinyl monomer on
f.2 from 95 to 5 wt. %, preferably from 90 to 10 wt. %,
particularly preferably from 70 to 40 wt. %, of one or more graft
bases having glass transition temperatures <10.degree. C.,
preferably <0.degree. C., particularly preferably
<-20.degree. C.
The graft base f.2 generally has a mean particle size (d50 value)
of from 0.05 to 10.00 .mu.m, preferably from 0.10 to 5.00 .mu.m,
more preferably from 0.15 to 1.00 .mu.m and particularly preferably
from 0.2 to 0.5 .mu.m.
The mean particle size d50 is the diameter above and below which in
each case 50 wt. % of the particles lie. It can be determined by
means of ultracentrifuge measurement (W. Scholtan, H. Lange,
Kolloid, Z. und Z. Polymere 250 (1972), 782-1796).
Monomers f.1 are preferably mixtures of f.1.1 from 50 to 99 parts
by weight of vinyl aromatic compounds and/or vinyl aromatic
compounds substituted on the ring (such as styrene,
.alpha.-methylstyrene, p-methylstyrene, p-chlorostyrene) and/or
(meth)acrylic acid (C1-C8)-alkyl esters, such as methyl
methacrylate, ethyl methacrylate, and f.1.2 from 1 to 50 parts by
weight of vinyl cyanides (unsaturated nitriles such as
acrylonitrile and methacrylonitrile) and/or (meth)acrylic acid
(C1-C8)-alkyl esters, such as methyl methacrylate, n-butyl
acrylate, tert-butyl acrylate, and/or derivatives (such as
anhydrides and imides) of unsaturated carboxylic acids, for example
maleic anhydride.
Preferred monomers f.1.1 are selected from at least one of the
monomers styrene, .alpha.-methylstyrene and methyl methacrylate,
preferred monomers f.1.2 are selected from at least one of the
monomers acrylonitrile, maleic anhydride and methyl methacrylate.
Particularly preferred monomers are f.1.1 styrene and f.1.2
acrylonitrile.
Graft bases f.2 suitable for the graft polymers according to
component f are, for example, diene rubbers, EP(D)M rubbers, that
is to say those based on ethylene/propylene and optionally diene,
acrylate, polyurethane, silicone, chloroprene, ethylene/vinyl
acetate and acrylate-silicone composite rubbers.
Preferred graft bases f.2 are diene rubbers, for example based on
butadiene and isoprene, or mixtures of diene rubbers or copolymers
of diene rubbers or mixtures thereof with further copolymerisable
monomers (e.g. according to f.1.1 and f.1.2), with the proviso that
the glass transition temperature of component f.2 is below
<10.degree. C., preferably <0.degree. C., particularly
preferably <-10.degree. C. Pure polybutadiene rubber is
particularly preferred.
The gel content of the graft base f.2 is at least 30 wt. %,
preferably at least 40 wt. %, particularly preferably at least 70
wt. % (measured in toluene).
The gel content of the graft base f.2 is determined at 25.degree.
C. in a suitable solvent (M. Hoffmann, H. Kromer, R. Kuhn,
Polymeranalytik I und II, Georg Thieme-Verlag, Stuttgart 1977).
Particularly preferred rubber-modified vinyl (co)polymers according
to component f are, for example, ABS polymers (emulsion, mass and
suspension ABS), as are described, for example, in DE-OS 2 035 390
(=U.S. Pat. No. 3,644,574) or in DE-OS 2 248 242 (=GB-PS 1 409 275)
or in Ullmanns, Enzyklopadie der Technischen Chemie, Vol. 19
(1980), p. 280 ff.
The graft copolymers according to component f are prepared by
radical polymerisation, for example by emulsion, suspension,
solution or mass polymerisation, preferably by emulsion or mass
polymerisation, particularly preferably by emulsion
polymerisation.
Particularly suitable graft rubbers are also ABS polymers which are
prepared by the emulsion polymerisation process by redox initiation
with an initiator system comprising organic hydroperoxide and
ascorbic acid according to U.S. Pat. No. 4,937,285.
Because it is known that, in the graft reaction, the graft monomers
are not necessarily grafted onto the graft base completely,
rubber-modified graft polymers according to component f are also
understood according to the invention as being those products which
are obtained by (co)polymerisation of the graft monomers f.1 in the
presence of the graft base f.2 and which also form during working
up.
Acrylate rubbers suitable as the graft base f.2 are preferably
polymers of acrylic acid alkyl esters, optionally with up to 40 wt.
%, based on f.2, of other polymerisable, ethylenically unsaturated
monomers. The preferred polymerisable acrylic acid esters include
C1- to C8-alkyl esters, for example methyl, ethyl, butyl, n-octyl
and 2-ethylhexyl esters; haloalkyl esters, preferably
halo-C1-C8-alkyl esters, such as chloroethyl acrylate, as well as
mixtures of these monomers.
For crosslinking, monomers having more than one polymerisable
double bond can be copolymerised. Preferred examples of
crosslinking monomers are esters of unsaturated monocarboxylic
acids having from 3 to 8 carbon atoms and unsaturated monohydric
alcohols having from 3 to 12 carbon atoms or saturated polyols
having from 2 to 4 OH groups and from 2 to 20 carbon atoms, such as
ethylene glycol dimethacrylate, allyl methacrylate; polyunsaturated
heterocyclic compounds, such as trivinyl and triallyl cyanurate;
polyfunctional vinyl compounds, such as di- and tri-vinylbenzenes;
but also triallyl phosphate and diallyl phthalate. Preferred
crosslinking monomers are allyl methacrylate, ethylene glycol
dimethacrylate, diallyl phthalate, and heterocyclic compounds which
contain at least three ethylenically unsaturated groups.
Particularly preferred crosslinking monomers are the cyclic
monomers triallyl cyanurate, triallyl isocyanurate,
triacryloyl-hexahydro-s-triazine, triallyl benzenes. The amount of
crosslinked monomers is preferably from 0.02 to 5.00 wt. %, in
particular from 0.05 to 2.00 wt. %, based on the graft base B.2. In
the case of cyclic crosslinking monomers having at least three
ethylenically unsaturated groups, it is advantageous to limit the
amount to less than 1 wt. % of the graft base f.2.
Preferred "other" polymerisable, ethylenically unsaturated monomers
which can optionally be used in addition to the acrylic acid esters
for the preparation of acrylate rubbers suitable as the graft base
f.2 are, for example, acrylonitrile, styrene,
.alpha.-methylstyrene, acrylamides, vinyl C1-C6-alkyl ethers,
methyl methacrylate, butadiene. Preferred acrylate rubbers as the
graft base f.2 are emulsion polymers having a gel content of at
least 60 wt. %.
Further suitable graft bases according to f.2 are silicone rubbers
having graft-active sites, as are described in DE-OS 3 704 657,
DE-OS 3 704 655, DE-OS 3 631 540 and DE-OS 3 631 539.
Rubber-free vinyl (co)polymers which can be used according to the
invention as component f are, for example and preferably, homo-
and/or co-polymers of at least one monomer from the group of the
vinyl aromatic compounds, vinyl cyanides (unsaturated nitriles),
(meth)acrylic acid (C1-C8)-alkyl esters, unsaturated carboxylic
acids, as well as derivatives (such as anhydrides and imides) of
unsaturated carboxylic acids.
Particularly suitable are (co)polymers of from 50 to 99 parts by
weight, preferably from 60 to 80 parts by weight, in particular
from 70 to 80 parts by weight, in each case based on the
(co)polymer, of at least one monomer selected from the group of the
vinyl aromatic compounds (such as, for example, styrene,
.alpha.-methylstyrene), vinyl aromatic compounds substituted on the
ring (such as, for example, p-methylstyrene, p-chlorostyrene) and
(meth)acrylic acid (C1-C8)-alkyl esters (such as, for example,
methyl methacrylate, n-butyl acrylate, tert-butyl acrylate), and
from 1 to 50 parts by weight, preferably from 20 to 40 parts by
weight, in particular from 20 to 30 parts by weight, in each case
based on the (co)polymer, of at least one monomer selected from the
group of the vinyl cyanides (such as, for example, unsaturated
nitriles such as acrylonitrile and methacrylonitrile),
(meth)acrylic acid (C1-C8)-alkyl esters (such as, for example,
methyl methacrylate, n-butyl acrylate, tert-butyl acrylate),
unsaturated carboxylic acids and derivatives of unsaturated
carboxylic acids (for example maleic anhydride and
N-phenyl-maleimide). The copolymer of styrene and acrylonitrile is
particularly preferred.
Such vinyl (co)polymers are known and can be prepared by radical
polymerisation, in particular by emulsion, suspension, solution or
mass polymerisation.
In an embodiment which is particularly preferred according to the
invention, the vinyl (co)polymers have a weight-average molar mass
M.sub.w (determined by gel chromatography in dichloromethane with
polystyrene calibration) of from 50,000 to 250,000 g/mol,
particularly preferably from 70,000 to 180,000 g/mol.
Component g
Additives according to component g which can be used according to
the invention are, for example, flameproofing agents (for example
halogen compounds or phosphorus compounds such as monomeric or
oligomeric organic phosphoric acid esters, phosphazenes or
phosphonate amines, in particular bisphenol A diphosphate,
resorcinol diphosphate and triphenyl phosphate), flameproofing
synergists (for example nano-scale metal oxides), smoke-inhibiting
additives (for example boric acid or borates), antidripping agents
(for example compounds of the substance classes of the fluorinated
polyolefins, of the silicones as well as aramid fibres),
antistatics (for example block copolymers of ethylene oxide and
propylene oxide, other polyethers or polyhydroxy ethers, polyether
amides, polyester amides or sulfonic acid salts), conductivity
additives other than the definition of component b, stabilisers
(for example UV/light stabilisers, heat stabilisers, antioxidants,
transesterification inhibitors, hydrolytic stabilisers), additives
having antibacterial action (for example silver or silver salts),
additives improving scratch resistance (for example silicone oils
or hard fillers such as (hollow) ceramics beads), IR absorbers,
optical brightening agents, fluorescent additives, fillers and
reinforcing substances other than the definition of component b
(for example talc, optionally ground glass fibres, (hollow) glass
or ceramics beads, mica, kaolin, CaCO.sub.3 and glass flakes),
colourings, ground thermoplastic polymers and Bronstedt-acidic
compounds as base acceptors, or mixtures of a plurality of the
mentioned additives.
The polymer mixtures prepared according to the invention are
preferably used in the production of injection-moulded articles or
of extrudates in which particular demands are made as regards the
homogeneity and freedom from defects of the surfaces.
Examples of moulded articles according to the invention are
profiles, films, casing parts of any kind, in particular casing
parts for computers, laptops, mobile telephones, television
surrounds; for office equipment such as monitors, printers,
copiers; for sheets, tubes, conduits for electrical installations,
windows, doors and profiles for the construction sector, interior
fitting and external applications; in the field of electrical
engineering, for example for switches and sockets. The moulded
articles according to the invention can also be used for interior
fittings for passenger vehicles, railway vehicles, ships, aircraft,
buses and other motor vehicles, as well as for automotive bodywork
parts. Further moulded articles are food and drinks packaging and
structural components which are galvanised or metallised after
injection moulding.
EXAMPLES
Raw Materials Used
a1
Linear polycarbonate based on bisphenol A having a weight-average
molecular weight M.sub.w of 17,000 g/mol (determined by GPC in
methylene chloride at 25.degree. C. with polycarbonate
calibration).
a2
Linear polycarbonate based on bisphenol A having a weight-average
molecular weight M.sub.w of 25,000 g/mol (determined by GPC in
methylene chloride at 25.degree. C. with polycarbonate
calibration).
a3
Linear polycarbonate based on bisphenol A having a weight-average
molecular weight M.sub.w of 28,000 g/mol (determined by GPC in
methylene chloride at 25.degree. C. with polycarbonate
calibration).
a4
Linear polycarbonate based on bisphenol A having a weight-average
molecular weight M.sub.w of 30,000 g/mol (determined by GPC in
methylene chloride at 25.degree. C. with polycarbonate
calibration).
a5
Linear polycarbonate based on bisphenol A having a weight-average
molecular weight M.sub.w of 36,000 g/mol (determined by GPC in
methylene chloride at 25.degree. C. with polycarbonate
calibration)
a6
Linear copolycarbonate of bisphenol A and
1,1-bis-(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane in a mixing
ratio of 70 wt. %:30 wt. % having a melt viscosity measured
according to ISO 11433 at a temperature of 340.degree. C. and a
shear rate of 1000 s.sup.-1 of 400 Pas.
a7
Linear polycarbonate of bisphenol A and
1,1-bis-(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane in a mixing
ratio of 30 wt. %:70 wt. % having a melt viscosity measured
according to ISO 11433 at a temperature of 340.degree. C. and a
shear rate of 1000 s.sup.-1 of 320 Pas.
a8
Component a2 ground to powder
a9
Linear polycarbonate based on bisphenol A having a weight-average
molecular weight M.sub.w of 32,000 g/mol (determined by GPC in
methylene chloride at 25.degree. C. with polycarbonate
calibration), ground to powder
b1
Black Pearls 800 (Cabot Corporation, Leuven, Belgium): pearled
pigment carbon black having a mean primary particle size determined
by scanning electron microscopy of 17 nm, a BET surface area
determined according to ISO 4652 by nitrogen adsorption of 210
m.sup.2/g and an oil adsorption number measured according to ISO
4656 with dibutyl phthalate (DBP) of 65 ml/100 g.
b2
Printex 85 (Evonik Degussa GmbH, Frankfurt/Main, Germany): pigment
carbon black having a mean primary particle size determined by
scanning electron microscopy of 16 nm, a BET surface area
determined according to ISO 4652 by nitrogen adsorption of 200
m.sup.2/g and an oil adsorption number measured according to ISO
4656 with dibutyl phthalate (DBP) of 48 ml/100 g.
b3
Chromium rutile pigment
b4
Iron oxide pigment
c1
Pentaerythritol tetrastearate (PETS)
c2
Glycerol monostearate (GMS)
c3
Stearyl stearate
c4
LDPE wax (low-density polyethylene wax)
d1
Linear polyethylene terephthalate having an intrinsic viscosity of
0.665 measured in phenol/o-dichlorobenzene (1:1 parts by weight) at
25.degree. C.
d2
Linear polybutylene terephthalate having a melt volume flow rate of
45 cm.sup.2/10 min at 250.degree. C. and 2.16 kg load
f1
Emulsion ABS granules with an A:B:S weight ratio of 20:24:56
f2
Mass ABS granules with an A:B:S weight ratio of 25:10:65
f3
Graft polymer consisting of 28 wt. % styrene-acrylonitrile
copolymer with a ratio of styrene to acrylonitrile of 71 to 29
parts by weight as shell on 72 wt. % of a particulate graft base as
core consisting of 46 parts by weight, based on the graft base, of
silicone rubber and 54 parts by weight, based on the graft base, of
butyl acrylate rubber, prepared by the emulsion polymerisation
process.
f4
Emulsions ABS graft in powder form with an A:B:S weight ratio of
12:58:30
f5
Emulsions ABS graft in powder form with an A:B:S weight ratio of
7:75:18
f6
Polymethyl methacrylate (PMMA)-grafted silicone-butyl acrylate
composite rubber graft in powder form, prepared by emulsion
polymerisation, consisting of a graft shell of 10 wt. %, based on
the graft, of polymethyl methacrylate and 90 wt. %, based on the
graft, of particulate silicone-butyl acrylate composite rubber base
with a silicone content, based on the silicone-butyl acrylate
composite rubber base, of 30 wt. % and a butyl acrylate content,
based on the silicone-butyl acrylate composite rubber base, of 70
wt. %.
f7
Styrene-acrylonitrile copolymer (SAN) with an A:S weight ratio of
24:76
g1
Bisphenol A-based oligophosphate
##STR00003## q=degree of oligomerisation g2
Polytetrafluoroethylene (PTFE) concentrate consisting of 50 wt. %
styrene-acrylonitrile (SAN) copolymer and 50 wt. % PTFE
g3
Stabilisers
g4
Talc with a d.sub.50 of 1.2 .mu.m.
g5
Water
A) Carbon Black Masterbatches
The carbon black/demoulding agent masterbatches 1 to 14 listed in
table 1 under component B were prepared as described below.
A.1) Mixing Units Used
Test Arrangement 1
A type MDK/E 46 co-kneader from Buss was used. FIG. 1 shows the
structure in principle. The mixture components were metered into
the feed hopper 1 of the Buss co-kneader 2. The mixture components
were there taken into the co-kneader 2 by the screw (not shown)
located on the inside and were conveyed axially. In the region of
the retaining ring 3, accumulation of the mixture components took
place, as well as melting of the demoulding agent, intimate mixing
of the mixture components and dispersion of the carbon black. In
the region of the retaining ring 4, accumulation of the melt
mixture took place, as well as further mixing of the mixture
components and dispersion of the carbon black. In the regions
between the feed hopper 1 and the retaining ring 3, the retaining
ring 3 and the retaining ring 4 and the retaining ring 4 and the
single-shaft extruder 5 flange-mounted on the co-kneader 2, the
kneading blades were so arranged on the screw shaft that the melt
mixture was conveyed axially in the direction of the single-shaft
extruder 5. In the single-shaft extruder 5, the melt mixture was
conveyed through the single-shaft screw (not shown) and degassed at
the degassing opening 6. At the end of the single-shaft extruder 5
there is a spray head (not shown) having a nozzle plate with 8
holes, each of which has a diameter of 2.5 mm. The melt strands
emerging from the nozzle plate were then granulated by means of a
hot-face water-ring granulating system (not shown) known to the
person skilled in the art to form granules having a length of up to
5 mm and were cooled. The water adhering to the granules was then
removed by means of a vibro screen (not shown) and subsequent
drying in a fluidised bed dryer (not shown).
Test Arrangement 2
As arrangement 1 but without retaining ring 3 (see FIG. 2), so that
the energy input of the co-kneader in test arrangement 2 is lower
as compared with test arrangement 1.
Test Arrangement 3
As arrangement 1 but with an additional metering hopper 7
downstream of retaining ring 3 (see FIG. 3), so that the carbon
black is added in two portions in two steps via metering hoppers 1
and 7.
Test Arrangement 4
An Evolum HT32 twin-screw extruder from Clextral with a housing
inside diameter of 32 mm, a ratio of screw outside diameter to
screw inside diameter of 1.55 and a length-to-diameter ratio of 44
was used. The twin-screw extruder has a housing consisting of 11
parts, in which two co-rotating, intermeshing shafts (not shown)
are arranged.
The structure of the extruder used is shown in principle in FIG.
4.
Metering of a portion of the pulverulent carbon black and of the
pulverulent demoulding agent was carried out by means of
differential proportioning weighers (not shown) via the feed hopper
8 into the main intake of the extruder in housing 9 (intake
housing).
In the region of housings 9 to 11 there is a feed zone in which the
mixture constituents are taken into the extruder in the solid state
and conveyed further.
In the region of housing 12 there is a plastification zone, which
consists of various conveying double- and triple-threaded kneading
blocks of different widths and a return element at the end of the
zone.
In the region of housings 13 and 14 there is a mixing zone, which
consists of various mixing, kneading and feed elements.
In housing 15, the remaining portion of the pulverulent carbon
black is metered into the extruder via a lateral feed device.
In the region of housings 16 and 17 there is a further mixing zone
which consists of various mixing, kneading and feed elements.
In housing part 18 (degassing housing) there is the degassing
opening 20, which is connected to a suction device (not shown).
In housing 19 (discharge housing) there the pressure build-up zone,
which is followed by a spray head (not shown) having a nozzle plate
with 6 holes, each of which has a diameter of 3.2 mm.
Test Arrangement 5
A type MDK/E 100 co-kneader from Buss was used. The structure
corresponded in principle to the structure of test arrangement
3.
Test Arrangement 6
A shear roller unit was used, as is described, for example, in EP
0707037 B1.
A.2) Preparation of Masterbatches B1-B16
Carbon black/demoulding agent masterbatches B1 to B4 were prepared
using the test arrangements, process parameters and formulations
indicated in Table 2.
The specific mechanical energy input (SME) indicated in Table 2 was
determined according to equation 1.
.pi..times..times. ##EQU00001## SME: specific mechanical energy
input in kWh/kg M: torque in Nm n: speed in l/min {dot over (m)}:
throughput in kg/h
Carbon black/demoulding agent masterbatch B5 was prepared using
test arrangement 5 from 58% b1 and 42% c1.
Carbon black/demoulding agent masterbatches B6 and B7 were prepared
using test arrangement 6 from 50% b1 and 50% c1 (B6) and 65% b1 and
35% c1 (B7).
Carbon black/demoulding agent masterbatches B8 to B14 were prepared
using the test arrangements, process parameters and formulations
indicated in Table 3. The specific mechanical energy input (SME)
indicated in Table 3 was calculated according to equation 1.
The carbon black/polycarbonate masterbatch B15 was supplied by
Color System S.p.a. Carbon black/polycarbonate masterbatch
consisting of 15 wt. % b1 and 85 wt. % of a bisphenol A-based
polycarbonate having a relative solution viscosity of 1.28
(measured in methylene chloride at 25.degree. C.).
The carbon black/polyethylene masterbatch B16 was supplied by Cabot
(trade name: Plasblak PE6130). Carbon black/polyethylene
masterbatch containing 50 wt. % carbon black.
B) PC Moulding Compositions
B.1) Mixing Units Used
Test Arrangement 7
An Evolum HT32 twin-screw extruder from Clextral having a housing
inside diameter of 32 mm, a ratio of screw outside diameter to
screw inside diameter of 1.55 and a length-to-diameter ratio of 36
was used. The twin-screw extruder has a housing consisting of 9
parts, in which two co-rotating, intermeshing shafts (not shown)
are arranged.
The structure of the extruder used is shown in principle in FIG.
5
Metering of all the components was carried out by means of
differential proportioning weighers (not shown) via the feed hopper
8a into the main intake of the extruder in housing 9a (intake
housing).
In the region of housings 9a to 13a there is a feed zone in which
the mixture constituents are taken into the extruder in the solid
state and conveyed further.
In the region of housings 14a and 16a there is a plastification
zone, which consists of various conveying double- and
triple-threaded kneading blocks of different widths and a return
element at the end of the zone.
In the region of housings 16a and 18a there is a mixing zone which
consists of various mixing and feed elements.
In housing part 18a (degassing housing) there is the degassing
opening 20a, which is connected to a suction device (not
shown).
In housing 19a (discharge housing) there is the pressure build-up
zone, which is followed by a spray head (not shown) having a nozzle
plate with 6 holes, each of which has a diameter of 3.2 mm.
Test Arrangement 8
As test arrangement 7 but with an injection valve 22 arranged at
the end of housing part 21, via which the liquid additive 1 is
metered in formulations 20 and 21 (FIG. 6).
Test Arrangement 9
A ZSK 25 WLE twin-screw extruder from Coperion Werner &
Pfleiderer having a housing inside diameter of 25.2 mm, a ratio of
screw outside diameter to screw inside diameter of 1.50 and a
length-to-diameter ratio of 48 was used. The twin-screw extruder
has a housing consisting of 13 parts, in which two co-rotating,
intermeshing shafts (not shown) are arranged. The structure of the
extruder used is shown in principle in FIG. 7. Metering of all the
components was carried out by means of differential proportioning
weighers (not shown) via the feed hopper 8c into the main intake of
the extruder in housing 9c (intake housing). In the region of
housings 9c to 12c there is a feed zone in which the mixture
constituents are taken into the extruder in the solid state and
conveyed further. In the region of housings 13c and 23
(intermediate plate) there is a plastification zone, which consists
of various conveying double- and triple-threaded kneading blocks of
different widths and a return element at the end of the zone. In
the region of housings 14c to 17c there are two mixing zones, which
consist of various mixing and feed elements. In housing part 18c
there is the degassing opening 20c, which is connected to a suction
device (not shown). In housing 19c (discharge housing) there is the
pressure build-up zone, which is followed by a spray head (not
shown) having a nozzle plate with 2 holes, each of which has a
diameter of 4.5 mm.
Test Arrangement 10
A ZSK 133Sc twin-screw extruder from Coperion Werner &
Pfleiderer having a housing inside diameter of 134.4 mm, a ratio of
screw outside diameter to screw inside diameter of 1.55 and a
length-to-diameter ratio of 31.5 was used. The twin-screw extruder
has a housing consisting of 10 parts, in which two co-rotating,
intermeshing shafts (not shown) are arranged. The structure of the
extruder used is shown in principle in FIG. 8. Metering of all the
components was carried out by means of differential proportioning
weighers (not shown) via the feed hopper 8d into the main intake of
the extruder in housing 9d (intake housing). In the region of
housings 9d to 11d there is a feed zone in which the mixture
constituents are taken into the extruder in the solid state and
conveyed further. In the region of housings 12d, 23a and 13d there
is a plastification zone, which consists of various conveying
double- and triple-threaded kneading blocks of different widths and
a return element at the end of the zone. In the region of housings
14d, 24a and 18d there is a mixing zone which consists of various
mixing and feed elements. In housing part 18d (degassing housing)
there is the degassing opening 20d, which is connected to a suction
device (not shown). In housing 19d (discharge housing) there is the
pressure build-up zone, which is followed by a spray head (not
shown) having a nozzle plate with 60 holes, each of which has a
diameter of 4.5 mm.
Test Arrangement 11
A ZSK 92Mc twin-screw extruder from Coperion Werner &
Pfleiderer having a housing inside diameter of 92.8 mm, a ratio of
screw outside diameter to screw inside diameter of 1.55 and a
length-to-diameter ratio of 40 was used. The twin-screw extruder
has a housing consisting of 10 parts, in which two co-rotating,
intermeshing shafts (not shown) are arranged. The structure of the
extruder used is shown in principle in FIG. 9. Metering of all the
components was carried out by means of differential proportioning
weighers (not shown) via the feed hopper 8e into the main intake of
the extruder in housing 9e (intake housing). In the region of
housings 9e to 13e there is a feed zone in which the mixture
constituents are taken into the extruder in the solid state and
conveyed further. In the region of housings 13e and 14e there is a
plastification zone, which consists of various conveying double-
and triple-threaded kneading blocks of different widths and a
return element at the end of the zone. In housing part 18e
(degassing housing) there is the degassing opening 20e, which is
connected to a suction device (not shown). In housing part 21a
there is an injection valve 22a, via which PETSLoxiolPS613,5Spezial
is added in liquid form. In the region of housings 21a and 26 there
is a mixing zone which consists of various mixing and feed
elements. In housing 19e (discharge housing) there is the pressure
build-up zone, which is followed by a spray head (not shown) having
a nozzle plate with 60 holes, each of which has a diameter of 4.5
mm.
B.2) Preparation of the PC Moulding Compositions
The process parameters used in the examples for the preparation of
PC moulding compositions are shown in Table 4. The specific
mechanical energy input (SME) indicated in Table 4 was determined
according to equation 1.
The PC moulding composition granules prepared in the examples were
processed by an injection moulding process to sheets with a glossy
surface having a size of 150 mm.times.105 mm.times.3.2 mm and to
test specimens having a size of 80 mm.times.10 mm.times.4 mm for
the Izod notched impact test according to ISO 180/1A.
The sheets with a glossy surface were produced on a type FM160
injection moulding machine from Klocknrer. This injection moulding
machine has a cylinder diameter of 45 mm. To that end, the PC
moulding composition granules were predried at 110.degree. C.
within a period of 4 hours. Processing by injection moulding was
carried out under the conditions characteristic for polycarbonates
or polycarbonate/ABS blends or polycarbonate/PET blends. An
injection moulding tool with a gloss finish (ISO N1) was used for
the production of the sheets.
The number of surface defects on the sheets with a glossy surface
was measured as described hereinbefore. 3 plates were measured in
each case, and the arithmetic mean was determined from the
results.
The Izod notched impact strength of the compound prepared was
determined according to ISO 180/1A on the test specimens for the
notched impact test. To that end, in each case 10 test specimens
were tested, and the arithmetic mean was determined from these
results.
Example 1
Comparison
An elastomer-containing polycarbonate blend having a melt volume
flow rate (MVR) of 27 cm.sup.3/10 min (measured according to ISO
1133 at 260.degree. C. and 5 kg) was prepared according to
formulation 1 (Table 1) using test arrangement 7. Carbon black
powder according to Table 1 was added as the carbon black
component.
For the preparation of the compound, a premix was first prepared
from components b (carbon black component), c (demoulding agent)
and g (additives) and also a9 given in Table 1 in the mentioned
amounts, Mixing of the premix was carried out in a container mixer
from Mixaco (type CM30 with Z tool) for 4.5 minutes at a speed of
300 l/min and a degree of filling of the mixer of 80%.
The premix and the remaining mixture constituents listed in Table 1
where then metered separately from one another, in each case by
means of a differential proportioning weigher (not shown), via the
feed hopper 8a into the main intake into housing 9a of the
extruder.
In the plastification zone and the mixing zone in the region of
housings 14a, 16a and 18a, the meltable mixture constituents were
melted, all the mixture constituents were dispersed and the melt
mixture was homogenised, the melt being degassed in the penultimate
housing part 18a.
The melt strands emerging from the nozzle plate were cooled in a
water bath and then granulated by means of a strand granulator.
The process parameters of the extruder and the number, measured as
described above, of surface defects, based on one square
centimeter, and the measured notched impact strength according to
ISO 180/1A are listed in Table 4 under Example 1.
Example 2
According to the Invention
An elastomer-containing polycarbonate blend having a melt volume
flow rate (MVR) of 27 cm.sup.-1/10 min (measured according to ISO
1133 at 260.degree. C. and 5 kg) was prepared according to
formulation 4 (see Table 1) using test arrangement 7. Carbon
black/demoulding agent masterbatch granules according to Table 1,
which were prepared as described under A.2, were added as the
carbon black component.
For the preparation of the compound, a premix was first prepared
from components b (carbon black component), f (elastomer) and g
(additives) given in Table 1 in the mentioned amounts. Preparation
of the premix and compounding of the moulding composition were
carried out as described in Example 1.
The process parameters of the extruder and the number, measured as
described above, of surface defects, based on one square
centimeter, and the measured notched impact strength according to
ISO 180/1A are listed in Table 4 under Example 2.
A comparison of Example 2 according to the invention with
Comparison Example 1 shows that, when the carbon black/demoulding
agent masterbatch is used, the number of surface defects is
markedly smaller and the notched impact strength at 23.degree. C.
and at 0.degree. C. is markedly higher than when the carbon black
powder is used. Both these findings indicate better dispersion of
the carbon black when the carbon black/demoulding agent masterbatch
is used, even though the specific mechanical energy input (SME) has
remained almost the same.
Example 3
Comparison
An elastomer-containing polycarbonate blend having a melt volume
flow rate (MVR) of 18 cm.sup.3/O-min (measured according to ISO
1133 at 260.degree. C. and 5 kg) was prepared according to
formulation 18 (see Table 1) using test arrangement 7. Carbon black
powder according to Table 1 was added as the carbon black
component.
For the preparation of the compound, a premix was first prepared
from components b (carbon black component), c (demoulding agent)
and g (additives) and also f4 given in Table 1 in the mentioned
amounts. Preparation of the premix and compounding of the moulding
composition were carried out as described in Example 1.
The process parameters of the extruder and the number, measured as
described above, of surface defects, based on one square
centimeter, are listed in Table 4 under Example 3.
Example 4
According to the Invention
An elastomer-containing polycarbonate blend having a melt volume
flow rate (MVR) of 18 cm.sup.3/10 min (measured according to ISO
1133 at 260.degree. C. and 5 kg) was prepared according to
formulation 19 (see Table 1) using test arrangement 7. Carbon
black/demoulding agent masterbatch granules according to Table 1,
which were prepared as described under A.2, were added as the
carbon black component.
For the preparation of the compound, a premix was first prepared
from components b (carbon black component) and g (additives) and
also f4 given in Table 1 in the mentioned amounts. Preparation of
the premix and compounding of the moulding composition were carried
out as described in Example 1.
The process parameters of the extruder and the number, measured as
described above, of surface defects, based on one square
centimeter, are listed in Table 4 under Example 4.
A comparison of Example 4 according to the invention with
Comparison Example 3 shows that, when the carbon black/demoulding
agent masterbatch is used, the number of surface defects is
markedly smaller than when the carbon black powder is used. Both
these findings indicate better dispersion of the carbon black when
the carbon black/demoulding agent masterbatch is used, even though
the specific mechanical energy input (SME) has remained the same. A
comparison of Examples 1 to 4 shows that, in the case of
elastomer-containing polycarbonate blends with markedly different
melt volume flow rates too, the number of surface defects when the
carbon black/demoulding agent masterbatch is used is markedly
smaller than when the carbon black powder is used.
Example 5
Comparison
A flame-protected elastomer-containing polycarbonate blend was
prepared according to formulation 20 (see Table 1) using test
arrangement 8. Carbon black powder according to Table 1 was added
as the carbon black component.
For the preparation of the compound, a premix was first prepared
from components b (carbon black component), c (demoulding agent),
g2, g3 and also f4 given in Table 1 in the mentioned amounts.
Mixing of the premix was carried out in a container mixer from
Mixaco (type CM30 with Z tool) for 4.5 minutes at a speed of 300
l/min degree of filling of the mixer of 80%.
The premix and the remaining mixture constituents listed in Table 1
were then metered separately from one another, in each case by
means of a differential proportioning weigher (not shown), via the
feed hopper 8b into the main intake into housing 9b of the
extruder.
In the plastification zone and the mixing zone in the region of
housings 12b and 13b, the meltable mixture constituents were
melted, the mixture constituents metered into the main intake were
dispersed and the melt mixture was homogenised. The melt was then
degassed in housing part 18b. In housing part 21, liquid g1
(flameproofing agent) was added via an injection valve 22 and
intimately mixed with the melt in the subsequent mixing zone in
housing parts 14b and 19b.
The melt strands emerging from the nozzle plate were cooled in a
water bath and then granulated by means of a strand granulator.
The process parameters of the extruder and the number, measured as
described above, of surface defects, based on one square
centimeter, and the measured notched impact strength according to
ISO 180/1A are listed in Table 4 under Example 5.
Example 6
According to the Invention
A flame-protected elastomer-containing polycarbonate blend was
prepared according to formulation 21 (see Table 1) using test
arrangement 8. Carbon black/demoulding agent masterbatch granules
according to Table 1, which were prepared as described under A.2,
were added as the carbon black component.
For the preparation of the compound, a premix was first prepared
from components b (carbon black component), g2, g3 and also f4
given in Table 1 in the mentioned amounts. Preparation of the
premix and compounding of the moulding composition were carried out
as described in Example 5.
The process parameters of the extruder and the number, measured as
described above, of surface defects, based on one square
centimeter, and the measured notched impact strength according to
ISO 180/1A are listed in Table 4 under Example 6.
A comparison of Example 6 according to the invention with
Comparison Example 5 shows that, when the carbon black/demoulding
agent masterbatch is used, the number of surface defects is
markedly smaller and the notched impact strength at 23.degree. C.
is higher than when the carbon black powder is used. Both these
findings indicate better dispersion of the carbon black when the
carbon black/demoulding agent masterbatch is used, even though the
specific mechanical energy input (SME) has remained almost the
same. A comparison of Examples 5 and 6 with Examples 1 to 4 shows
that, even when a liquid flameproofing agent is added to an
elastomer-containing polycarbonate blend, the number of surface
defects is markedly smaller when the carbon black/demoulding agent
masterbatch is used than when the carbon black powder is used.
Example 7
Comparison
A polycarbonate compound having a melt volume flow rate (MVR) of
9.5 cm.sup.3/10 min (measured according to ISO 1133 at 300.degree.
C. and 1.2 kg) was prepared according to formulation 22 (see Table
1) using test arrangement 7. Carbon black powder according to Table
1 was added as the carbon black component.
For the preparation of the compound, a premix was first prepared
from components b (carbon black component), c (demoulding agent)
and also a9 given in Table 1 in the mentioned amounts. Preparation
of the premix and compounding of the moulding composition were
carried out as described in Example 1.
The process parameters of the extruder and the number, measured as
described above, of surface defects, based on one square
centimeter, are listed in Table 4 under Example 7.
Example 8
According to the Invention
A polycarbonate compound having a melt volume flow rate (MVR) of
9.5 cm.sup.3/10 min (measured according to ISO 1133 at 300.degree.
C. and 1.2 kg) was prepared according to formulation 23 (see Table
1) using test arrangement 7. Carbon black/demoulding agent
masterbatch granules according to Table 1, which were prepared as
described under A.2, were added as the carbon black component.
For the preparation of the compound, a premix was first prepared
from components b (carbon black component), c (demoulding agent)
and also a9 given in Table 1 in the mentioned amounts. Preparation
of the premix and compounding of the moulding composition were
carried out as described in Example 1.
The process parameters of the extruder and the number, measured as
described above, of surface defects, based on one square
centimeter, are listed in Table 4 under Example 8.
A comparison of Example 8 according to the invention with
Comparison Example 7 shows that, when the carbon black/demoulding
agent masterbatch is used, the number of surface defects is smaller
than when the carbon black powder is used. Both these findings
indicate better dispersion of the carbon black when the carbon
black/demoulding agent masterbatch is used, even though the
specific mechanical energy input (SME) has remained almost the
same.
Example 9
Comparison
A polycarbonate compound having a melt volume flow rate (MVR) of 5
cm.sup.3/10 min (measured according to ISO 1133 at 300.degree. C.
and 1.2 kg) was prepared according to formulation 24 (see Table 1)
using test arrangement 7. Carbon black powder according to Table 1
was added as the carbon black component.
For the preparation of the compound, a premix was first prepared
from components b (carbon black component), c (demoulding agent)
and also a9 given in Table 1 in the mentioned amounts. Preparation
of the premix and compounding of the moulding composition were
carried out as described in Example 1.
The process parameters of the extruder and the number, measured as
described above, of surface defects, based on one square
centimeter, are listed in Table 4 under Example 9.
Example 10
According to the Invention
A polycarbonate compound having a melt volume flow rate (MVR) of 5
cm.sup.3/10 min (measured according to ISO 1133 at 300.degree. C.
and 1.2 kg) was prepared according to formulation 25 (see Table 1)
using test arrangement 7. Carbon black/demoulding agent masterbatch
granules according to Table 1, which were prepared as described
under A.2, were added as the carbon black component.
For the preparation of the compound, a premix was first prepared
from components b (carbon black component), c (demoulding agent)
and also a9 given in Table 1 in the mentioned amounts. Preparation
of the premix and compounding of the moulding composition were
carried out as described in Example 1.
The process parameters of the extruder and the number, measured as
described above, of surface defects, based on one square
centimeter, are listed in Table 4 under Example 10.
A comparison of Example 10 according to the invention with
Comparison Example 9 shows that, when the carbon black/demoulding
agent masterbatch is used, the number of surface defects is smaller
than when the carbon black powder is used. Both these findings
indicate better dispersion of the carbon black when the carbon
black/demoulding agent masterbatch is used, even though the
specific mechanical energy input (SME) has remained the same.
Example 11
Comparison
A high-temperature-resistant polycarbonate compound (Vicat
softening temperature 203.degree. C. measured according to ISO 306
at 50 N; 120.degree. C./h) having a melt volume flow rate (MVR) of
8 cm.sup.3/10 min (measured according to ISO 1133 at 330.degree. C.
and 2.16 kg) was prepared according to formulation 28 (see Table 1)
using test arrangement 7. Carbon black powder according to Table 1
was added as the carbon black component.
For the preparation of the compound, a premix was first prepared
from components b (carbon black component), c (demoulding agent)
and also a9 given in Table 1 in the mentioned amounts. Preparation
of the premix and compounding of the moulding composition were
carried out as described in Example 1.
The process parameters of the extruder and the number, measured as
described above, of surface defects, based on one square
centimeter, are listed in Table 4 under Example 11.
Example 12
According to the Invention
A high-temperature-resistant polycarbonate compound (Vicat
softening temperature 203.degree. C. measured according to ISO 306
at 50 N; 120.degree. C./h) having a melt volume flow rate (MVR) of
8 cm.sup.3/10 min (measured according to ISO 1133 at 300.degree. C.
and 1.2 kg) was prepared according to formulation 29 (see Table 1)
using test arrangement 7. Carbon black/demoulding agent masterbatch
granules according to Table 1, which were prepared as described
under A.2, were added as the carbon black component.
For the preparation of the compound, a premix was first prepared
from components b (carbon black component), c (demoulding agent)
and also a9 given in Table 1 in the mentioned amounts. Preparation
of the premix and compounding of the moulding composition were
carried out as described in Example 1.
The process parameters of the extruder and the number, measured as
described above, of surface defects, based on one square
centimeter, are listed in Table 4 under Example 12.
A comparison of Example 12 according to the invention with
Comparison Example 11 shows that, when the carbon black/demoulding
agent masterbatch is used, the number of surface defects is
markedly smaller than when the carbon black powder is used. Both
these findings indicate better dispersion of the carbon black when
the carbon black/demoulding agent masterbatch is used, even though
the specific mechanical energy input (SME) has remained the
same.
Example 13
Comparison
A high-temperature-resistant polycarbonate compound (Vicat
softening temperature 184.degree. C. measured according to ISO 306
at 50 N; 120.degree. C./h) having a melt volume flow rate (MVR) of
10 cm.sup.3/10 min (measured according to ISO 1133 at 330.degree.
C. and 2.16 kg) was prepared according to formulation 30 (see Table
1) using test arrangement 7. Carbon black powder according to Table
1 was added as the carbon black component.
For the preparation of the compound, a premix was first prepared
from components b (carbon black component) and a9 given in Table 1
in the mentioned amounts. Preparation of the premix and compounding
of the moulding composition were carried out as described in
Example 1.
The process parameters of the extruder and the number, measured as
described above, of surface defects, based on one square
centimeter, are listed in Table 4 under Example 13.
Example 14
According to the Invention
A high-temperature-resistant polycarbonate compound (Vicat
softening temperature 184.degree. C. measured according to ISO 306
at 50 N; 120.degree. C./h) having a melt volume flow rate (MVR) of
cm.sup.3/10 min (measured according to ISO 1133 at 300.degree. C.
and 1.2 kg) was prepared according to formulation 31 (see Table 1)
using test arrangement 7. Carbon black/demoulding agent masterbatch
granules according to Table 1, which were prepared as described
under A.2, were added as the carbon black component.
For the preparation of the compound, a premix was first prepared
from components b (carbon black component) and a9 given in Table 1
in the mentioned amounts. Preparation of the premix and compounding
of the moulding composition were carried out as described in
Example 1.
The process parameters of the extruder and the number, measured as
described above, of surface defects, based on one square
centimeter, are listed in Table 4 under Example 14.
A comparison of Example 14 according to the invention with
Comparison Example 13 shows that, when the carbon black/demoulding
agent masterbatch is used, the number of surface defects is
markedly smaller than when the carbon black powder is used. Both
these findings indicate better dispersion of the carbon black when
the carbon black/demoulding agent masterbatch is used, even though
the specific mechanical energy input (SME) has remained almost the
same.
A comparison of Examples 7 to 14 shows that, in the case of
polycarbonate compounds with markedly different melt volume flow
rates and Vicat softening temperatures too, the number of surface
defects is markedly smaller when the carbon black/demoulding agent
masterbatch is used than when the carbon black powder is used.
A comparison of Examples 7 to 14 with Examples 1 to 4 shows that,
even in the case of pure polycarbonate compounds without the
addition of elastomer-containing components, the number of surface
defects is markedly smaller when the carbon black/demoulding agent
masterbatch is used than when the carbon black powder is used.
Example 15
Comparison
An elastomer-containing polycarbonate blend having a melt volume
flow rate (MVR) of 17 cm.sup.3/10 min (measured according to ISO
1133 at 260.degree. C. and 5 kg) was prepared according to
formulation 35 (Table 1) using test arrangement 9. Carbon black
powder according to Table 1 was added as the carbon black
component.
For the preparation of the compound, a premix was first prepared
from components b (carbon black component), c (demoulding agent), g
(additives) and f6 given in Table 1 in the mentioned amounts.
Mixing of the premix was carried out in a container mixer from
Mixaco (type CM30 with Z tool) for 4.5 minutes at a speed of 300
l/min and a degree of filling of the mixer of 80%.
The premix and the remaining mixture constituents listed in Table 1
were then metered separately from one another, in each case by
means of a differential proportioning weigher (not shown), via the
feed hopper 8c into the main intake into housing 9c of the
extruder.
In the plastification zone in the region of housings 12c and 13c,
the meltable mixture constituents were melted and all the mixture
constituents were dispersed. In the mixing zone in the region of
housings 24, 16c, 25 and 17c, the melt mixture was intimately mixed
and homogenised. The melt was degassed in the penultimate housing
part 18c.
The melt strands emerging from the nozzle plate were cooled in a
water bath and then granulated by means of a strand granulator.
The process parameters of the extruder are listed in Table 4 under
Example 15. The notched impact strength at different ambient
temperatures, measured according to ISO 180/1A, is shown in
diagrams FIG. 11 for an injection moulding material temperature of
260.degree. C. and FIG. 12 for an injection moulding material
temperature of 300.degree. C. Each measuring point in the diagrams
represents the mean value of 10 measurements. The number pairs
additionally given at the measuring points indicate the number of
ductile fractured or brittle fractured test specimens. "10/0"
means, for example, that all 10 test specimens tested are ductile
fractured.
Example 16
According to the Invention
An elastomer-containing polycarbonate blend having a melt volume
flow rate (MVR) of 17 cm.sup.3/10 min (measured according to ISO
1133 at 260.degree. C. and 5 kg) was prepared according to
formulation 36 (see Table 1) using test arrangement 9. Carbon
black/demoulding agent masterbatch granules according to Table 1
which were prepared as described under A.2, were added as the
carbon black component.
For the preparation of the compound, a premix was first prepared
from components b (carbon black component), g (additives) and f6
given in Table 1 in the mentioned amounts. Preparation of the
premix and compounding of the moulding composition were carried out
as described in Example 15.
The process parameters of the extruder are listed in Table 4 under
Example 16. The notched impact strength at different ambient
temperatures, measured according to ISO 180/1A, is shown in
diagrams FIG. 11 for an injection moulding material temperature of
260.degree. C. and FIG. 12 for an injection moulding material
temperature of 300.degree. C. Each measuring point in the diagrams
represents the mean value of 10 measurements. The number pairs
additionally given at the measuring points indicate the number of
ductile fractured or brittle fractured test specimens. "10/0"
means, for example, that all 10 test specimens tested are ductile
fractured.
A comparison of Example 16 according to the invention with
Comparison Example 15 shows that, when the carbon black/demoulding
agent masterbatch is used, the notched impact strength is markedly
higher and the transition from ductile to brittle fracture
behaviour occurs at lower temperatures than when the carbon black
powder is used. This indicates better dispersion of the carbon
black when the carbon black/demoulding agent masterbatch is used,
even though the specific mechanical energy input (SME) has remained
almost the same.
Example 17
Comparison
An elastomer-containing polycarbonate blend having a melt volume
flow rate (MVR) of 27 cm.sup.3/10 min (measured according to ISO
1133 at 260.degree. C. and 5 kg) was prepared according to
formulation 17 (see Table 1) using test arrangement 7. B16 (carbon
black/polyethylene masterbatch Plasblak PE6130 (50% carbon black)
from Cabot) according to Table 1 was added as the carbon black
component.
For the preparation of the compound, a premix was first prepared
from components b (carbon black component), c (demoulding agent), g
(additives) and f3 given in Table 1 in the mentioned amounts.
Preparation of the premix and compounding of the moulding
composition were carried out as described in Example 1.
The process parameters of the extruder and the number, measured as
described above, of surface defects, based on one square
centimeter, are listed in Table 4 under Example 17.
Example 18
Comparison
An elastomer-containing polycarbonate blend having a melt volume
flow rate (MVR) of 27 cm.sup.3/10 min (measured according to ISO
1133 at 260.degree. C. and 5 kg) was prepared according to
formulation 16 (see Table 1) using test arrangement 7. The carbon
black/polycarbonate masterbatch B15 (PC Black 91024 (15% carbon
black) from Color Systems) according to Table 1 was added as the
carbon black component.
For the preparation of the compound, a premix was first prepared
from components b (carbon black component), c (demoulding agent)
and g (additives) and also a9 given in Table 1 in the mentioned
amounts. Preparation of the premix and compounding of the moulding
composition were carried out as described in Example 1.
The process parameters of the extruder and the number, measured as
described above, of surface defects, based on one square
centimeter, are listed in Table 4 under Example 18.
Example 19
According to the Invention
An elastomer-containing polycarbonate blend having a melt volume
flow rate (MVR) of 27 cm.sup.3/10 min (measured according to ISO
1133 at 260.degree. C. and 5 kg) was prepared according to
formulation 4 (see Table 1) using test arrangement 7. Carbon
black/demoulding agent masterbatch granules according to Table 1,
which were prepared as described under A.2, were added as the
carbon black component.
For the preparation of the compound, a premix was first prepared
from components b (carbon black component), g (additives) and f3
given in Table 1 in the mentioned amounts. Preparation of the
premix and compounding of the moulding composition were carried out
as described in Example 1.
The process parameters of the extruder and the number; measured as
described above, of surface defects, based on one square
centimeter, are listed in Table 4 under Example 19.
A comparison of Example 19 according to the invention with
Comparison Examples 17 and 18 shows that, when the carbon
black/demoulding agent masterbatch is used, the number of surface
defects is markedly smaller than when masterbatches based on
polyethylene (B16) or polycarbonate (B15) are used. Both these
findings indicate better dispersion of the carbon black when the
carbon black/demoulding agent masterbatch is used, even though the
specific mechanical energy input (SME) has remained almost the
same.
Example 20
Comparison
An elastomer- and polyester-containing polycarbonate blend having a
melt volume flow rate (MVR) of 12 cm.sup.3/10 min (measured
according to ISO 1133 at 260.degree. C. and 5 kg) was prepared
according to formulation 32 (Table 1) using test arrangement 10.
Carbon black powder according to Table 1 was added as the carbon
black component.
For the preparation of the compound, a premix was first prepared
from components b (carbon black component), c (demoulding agent)
and g (additives) and also a8 given in Table 1 in the mentioned
amounts. Mixing of the premix was carried out in a container mixer
from Mixaco (type CM1000 with MB tool) for 4.5 minutes at a speed
of 425 l/min and a degree of filling of the mixer of 80%.
The premix and the remaining mixture constituents listed in Table 1
were then metered separately from one another, in each case by
means of a differential proportioning weigher (not shown), via the
feed hopper 8d into the main intake into housing 9d of the
extruder.
In the plastification zone in the region of housings 12d, 23a and
13d, the meltable mixture constituents were melted and all the
mixture constituents were dispersed. In the mixing zone in the
region of housings 14d, 24a and 18d, the mixture constituents were
intimately mixed and the melt mixture was homogenised. The melt
mixture was degassed in the penultimate housing part 8d.
The melt strands emerging from the nozzle plate were cooled in a
water bath and then granulated by means of a strand granulator.
The process parameters of the extruder and the number, measured as
described above, of surface defects, based on one square
centimeter, are listed in Table 4 under Example 20.
Example 21
Comparison
An elastomer- and polyester-containing polycarbonate blend having a
melt volume flow rate (MVR) of 12 cm.sup.3/10 min (measured
according to ISO 1133 at 260.degree. C. and 5 kg) was prepared
according to formulation 33 (Table 1) using test arrangement 10.
B86 (carbon black/polyethylene masterbatch Plasblak PE6130 (50%
carbon black) from Cabot) according to Table 1 was added as the
carbon black component.
For the preparation of the compound, a premix was first prepared
from components b (carbon black component), c (demoulding agent)
and g (additives) and also a8 given in Table 1 in the mentioned
amounts. Preparation of the premix and compounding of the moulding
composition were carried out as described in Example 20.
The process parameters of the extruder as well as the number,
measured as described above, of surface defects, based on one
square centimeter, are listed in Table 4 under Example 21.
Example 22
According to the Invention
An elastomer-containing polycarbonate blend having a melt volume
flow rate (MVR) of 12 cm.sup.3/10 min (measured according to ISO
1133 at 260.degree. C. and 5 kg) was prepared according to
formulation 34 (see Table 1) using test arrangement 10. Carbon
black/demoulding agent masterbatch granules according to Table 1,
which were prepared as described under A.2, were added as the
carbon black component.
For the preparation of the compound, a premix was first prepared
from components b (carbon black component), c (demoulding agent)
and g (additives) and also a8 given in Table 1 in the mentioned
amounts. Preparation of the premix and compounding of the moulding
composition were carried out as described in Example 20.
The process parameters of the extruder and the number, measured as
described above, of surface defects, based on one square
centimeter, are listed in Table 4 under Example 22.
A comparison of Example 22 according to the invention with
Comparison Examples 20 and 21 shows that, for elastomer- and
polyester-containing polycarbonate blends too, the number of
surface defects is markedly smaller when the carbon
black/demoulding agent masterbatch is used than when carbon black
powder and a carbon black/polyethylene masterbatch according to the
prior art are used. Both these findings indicate better dispersion
of the carbon black when the carbon black/demoulding agent
masterbatch is used, even though the specific mechanical energy
input (SME) has remained almost the same.
At the same time it is shown that, even with an extruder having a
larger screw outside diameter (133 mm), the number of surface
defects is markedly smaller when the carbon black/demoulding agent
masterbatch is used than when carbon black powder or carbon black
masterbatch according to the prior art is used.
Example 23
Comparison
A polycarbonate compound having a melt volume flow rate (MVR) of 19
cm.sup.3/10 min (measured according to ISO 1133 at 300.degree. C.
and 1.2 kg) was prepared according to formulation 26 (see Table 1)
using test arrangement 11. Carbon black powder according to Table 1
was added as the carbon black component.
For the preparation of the compound, a premix was first prepared
from components b (carbon black component), c (demoulding agent)
and g (additives) and also a8 given in Table 1 in the mentioned
amounts. Mixing of the premix was carried out in a container mixer
from Mixaco (type CM1000 with MB tool). Components b, g and a8 were
first introduced into the mixing container and mixed for 2 minutes
at a speed of 250 l/min and a degree of filling of the mixer of
80%. Component c was then added to the premixed components in the
mixing container and mixed for 1.5 minutes at a speed of 350
l/min.
The premix and the remaining mixture constituents listed in Table 1
were then metered separately from one another, in each case by
means of a differential proportioning weigher (not shown), via the
feed hopper 8e into the main intake into housing 9e of the
extruder.
In the plastification zone and the mixing zone in the region of
housings 13e and 14e, the meltable mixture constituents were melted
and all the mixture constituents were dispersed. In housing 18e,
the melt was degassed. In housing 21a, liquid g1 (flameproofing
agent) was injected into the melt via an injection nozzle 22a and
intimately mixed with the melt in the subsequent mixing zone in the
region of housings 21a, 26 and 19e, and the melt mixture was
homogenised.
The melt strands emerging from the nozzle plate were cooled in a
water bath and then granulated by means of a strand granulator.
The process parameters of the extruder and the number, measured as
described above, of surface defects, based on one square
centimeter, are listed in Table 4 under Example 23.
Example 24
According to the Invention
A polycarbonate compound having a melt volume flow rate (MVR) of 19
cm.sup.3/10 min (measured according to ISO 1133 at 30.degree. C.
and 1.2 kg) was prepared according to formulation 27 (see Table 1)
using test arrangement 11. Carbon black/demoulding agent
masterbatch granules according to Table 1, which were prepared as
described under A.2, were added as the carbon black component.
For the preparation of the compound, a premix was first prepared
from components b (carbon black component), c (demoulding agent)
and also a8 given in Table 1 in the mentioned amounts. Mixing of
the premix was carried out in a container mixer from Mixaco (type
CM1000 with MB tool). Components b, g and a8 were first introduced
into the mixing container and mixed for 2 minutes at a speed of 250
l/min and a degree of filling of the mixer of 80%. Component c was
then added to the premixed components in the mixing container and
mixed for 1.5 minutes at a speed of 350 l/min.
Compounding of the moulding composition was carried out as
described in Example 23.
The process parameters of the extruder and the number, measured as
described above, of surface defects, based on one square
centimeter, are listed in Table 4 under Example 24.
A comparison of Example 24 according to the invention with
Comparison Example 23 shows that, when the carbon black/demoulding
agent masterbatch is used, the number of surface defects is
markedly smaller than when the carbon black powder is used. Both
these findings indicate better dispersion of the carbon black when
the carbon black/demoulding agent masterbatch is used, even though
the specific mechanical energy input (SME) was higher in Example 23
than in Example 24.
At the same time it is shown that, for a polycarbonate compound
too, in an extruder having a larger screw outside diameter (92 mm),
the number of surface defects is markedly smaller when the carbon
black/demoulding agent masterbatch is used than when carbon black
powder is used.
Example 25
According to the Invention
An elastomer-containing polycarbonate blend having a melt volume
flow rate (MVR) of 27 cm.sup.3/10 min (measured according to ISO
1133 at 260.degree. C. and 5 kg) was prepared according to
formulation 10 (see Table 1) using test arrangement 7. Carbon
black/demoulding agent masterbatch granules containing 40 wt. %
carbon black according to Table 1, which were prepared as described
under A.2, were added as the carbon black component.
For the preparation of the compound, a premix was first prepared
from components b (carbon black component), g (additives) and f3
given in Table 1 in the mentioned amounts. Preparation of the
premix and compounding of the moulding composition were carried out
as described in Example 1.
The process parameters of the extruder and the number, measured as
described above, of surface defects, based on one square
centimeter, are listed in Table 4 under Example 25.
Example 26
According to the Invention
An elastomer-containing polycarbonate blend having a melt volume
flow rate (MVR) of 27 cm.sup.3/10 min (measured according to ISO
1133 at 260.degree. C. and 5 kg) was prepared according to
formulation 12 (see Table 1) using test arrangement 7. Carbon
black/demoulding agent masterbatch granules containing 45 wt. %
carbon black according to Table 1, which were prepared as described
under A.2, were added as the carbon black component.
The procedure in the preparation of the polycarbonate blend
corresponded to that of Example 25.
The process parameters of the extruder and the number, measured as
described above, of surface defects, based on one square
centimeter, are listed in Table 4 under Example 26.
Example 27
An elastomer-containing polycarbonate blend having a melt volume
flow rate (MVR) of 27 cm.sup.3/10 min (measured according to ISO
1133 at 260.degree. C. and 5 kg) was prepared according to
formulation 9 (see Table 1) using test arrangement 7. Carbon
black/demoulding agent masterbatch granules containing 50 wt. %
carbon black according to Table 1, which were prepared as described
under A.2, were added as the carbon black component.
The procedure in the preparation of the polycarbonate blend
corresponded to that of Example 25.
The process parameters of the extruder and the number, measured as
described above, of surface defects, based on one square
centimeter, are listed in Table 4 under Example 27.
Example 28
According to the Invention
An elastomer-containing polycarbonate blend having a melt volume
flow rate (MVR) of 27 cm.sup.3/10 min (measured according to ISO
1133 at 260.degree. C. and 5 kg) was prepared according to
formulation 6 (see Table 1) using test arrangement 7. Carbon
black/demoulding agent masterbatch granules containing 58 wt. %
carbon black according to Table 1, which were prepared as described
under A.2, were added as the carbon black component.
The procedure in the preparation of the polycarbonate blend
corresponded to that of Example 25.
The process parameters of the extruder and the number, measured as
described above, of surface defects, based on one square
centimeter, are listed in Table 4 under Example 28.
Example 29
According to the Invention
An elastomer-containing polycarbonate blend having a melt volume
flow rate (MVR) of 27 cm.sup.3/10 min (measured according to ISO
1133 at 260.degree. C. and 5 kg) was prepared according to
formulation 11 (see Table 1) using test arrangement 7. Carbon
black/demoulding agent masterbatch granules containing 60 wt. %
carbon black according to Table 1, which were prepared as described
under A.2, were added as the carbon black component.
The procedure in the preparation of the polycarbonate blend
corresponded to that of Example 25.
The process parameters of the extruder and the number, measured as
described above, of surface defects, based on one square
centimeter, are listed in Table 4 under Example 29.
Example 30
According to the Invention
An elastomer-containing polycarbonate blend having a melt volume
flow rate (MVR) of 27 cm.sup.3/10 min (measured according to ISO
1133 at 260.degree. C. and 5 kg) was prepared according to
formulation 8 (see Table 1) using test arrangement 7. Carbon
black/demoulding agent masterbatch granules containing 65 wt. %
carbon black according to Table 1, which were prepared as described
under A.2, were added as the carbon black component.
The procedure in the preparation of the polycarbonate blend
corresponded to that of Example 25.
The process parameters of the extruder and the number, measured as
described above, of surface defects, based on one square
centimeter, are listed in Table 4 under Example 30.
A comparison of Examples 25 to 30 according to the invention with
Comparison Example 1 shows that, even when carbon black/demoulding
agent masterbatches having carbon black contents varying from 40
wt. % to 65 wt. % are used, the number of surface defects is
markedly lower than when carbon black powder is used. With a carbon
black content of 65 wt. % in the masterbatch (Example 30), however,
the number of surface defects is higher than with 40 wt. % to 60
wt. %, so that 65 wt. % represents the upper carbon black
concentration for good dispersion.
In tests with carbon black concentrations less than 40 wt. %, it
was not possible to form a strand because the carbon
black-demoulding agent composition had too low a viscosity and was
tacky. In the tests, therefore, a carbon black concentration of 40
wt. % represented the lower carbon black concentration which could
still be processed without problems.
Example 31
According to the Invention
An elastomer-containing polycarbonate blend having a melt volume
flow rate (MVR) of 27 cm.sup.3/10 min (measured according to ISO
1133 at 260.degree. C. and 5 kg) was prepared according to
formulation 7 (see Table 1) using test arrangement 7. Carbon
black/demoulding agent masterbatch granules according to Table 1,
which were prepared as described under A.2, were added as the
carbon black component.
For the preparation of the compound, a premix was first prepared
from components b (carbon black component), g (additives) and f3
given in Table 1 in the mentioned amounts. Preparation of the
premix and compounding of the moulding composition were carried out
as described in Example 1.
The process parameters of the extruder and the number, measured as
described above, of surface defects, based on one square
centimeter, are listed in Table 4 under Example 31.
A comparison of Examples 2, 27 and 31 according to the invention
with Comparison Example 1 shows that, when carbon black/demoulding
agent masterbatches produced either using a co-kneader or using a
twin-screw extruder or using shear rollers are used, the number of
surface defects is markedly smaller than when carbon black powder
is used.
Example 32
According to the Invention
An elastomer-containing polycarbonate blend having a melt volume
flow rate (MVR) of 27 cm.sup.3/10 min (measured according to ISO
1133 at 260.degree. C. and 5 kg) was prepared according to
formulation 13 (see Table 1) using test arrangement 7. For the
preparation of the compound, a premix was first prepared from
components b (carbon black component), g (additives) and f3 given
in Table 1 in the mentioned amounts. Preparation of the premix and
compounding of the moulding composition were carried out as
described in Example 1.
The process parameters of the extruder and the number, measured as
described above, of surface defects, based on one square
centimeter, are listed in Table 4 under Example 32.
Example 33
According to the Invention
An elastomer-containing polycarbonate blend having a melt volume
flow rate (MVR) of 27 cm.sup.3/10 min (measured according to ISO
1133 at 260.degree. C. and 5 kg) was prepared according to
formulation 14 (see Table 1) using test arrangement 7. The
procedure in the preparation of the polycarbonate blend
corresponded to that of Example 32.
The process parameters of the extruder and the number, measured as
described above, of surface defects, based on one square
centimeter, are listed in Table 4 under Example 33.
Example 34
According to the Invention
An elastomer-containing polycarbonate blend having a melt volume
flow rate (MVR) of 27 cm.sup.3/10 min (measured according to ISO
1133 at 260.degree. C. and 5 kg) was prepared according to
formulation 15 (see Table 1) using test arrangement 7. The
procedure in the preparation of the polycarbonate blend
corresponded to that of Example 32.
The process parameters of the extruder and the number, measured as
described above, of surface defects, based on one square
centimeter, are listed in Table 4 under Example 34.
A comparison of Examples 27, 32, 33 and 34 according to the
invention with Comparison Example 1 shows that, with c1 or c3 or c4
in the carbon black/demoulding agent masterbatch, when the carbon
black/demoulding agent masterbatch so prepared is used, the number
of surface defects is markedly smaller than with carbon black
powder. Although with c2 in the carbon black/demoulding agent
masterbatch, the number of surface defects is larger when the
carbon black/demoulding agent masterbatch so prepared is used than
with c1, c3 or c4, it is still markedly smaller than with carbon
black powder.
Example 35
According to the Invention
An elastomer-containing polycarbonate blend having a melt volume
flow rate (MVR) of 27 cm.sup.3/10 min (measured according to ISO
1133 at 260.degree. C. and 5 kg) was prepared according to
formulation 5 (see Table 1) using test arrangement 7. For the
preparation of the compound, a premix was first prepared from
components b (carbon black component), g (additives) and f3 given
in Table 1 in the mentioned amounts. Preparation of the premix and
compounding of the moulding composition were carried out as
described in Example 1.
The process parameters of the extruder and the number, measured as
described above, of surface defects, based on one square
centimeter, and the measured notched impact strength according to
ISO 180/1A are listed in Table 4 under Example 35.
A comparison of Examples 2 and 35 according to the invention with
Comparison Example 1 shows that, with both b2 and b1 as carbon
black in the carbon black/demoulding agent masterbatch, when the
carbon black/demoulding agent masterbatch so prepared is used, the
number of surface defects is markedly smaller and the notched
impact strength at 23.degree. C. and at 0.degree. C. is markedly
higher than with carbon black powder.
Example 36
According to the Invention
An elastomer-containing polycarbonate blend having a melt volume
flow rate (MVR) of 27 cm.sup.3/10 min (measured according to ISO
1133 at 260.degree. C. and 5 kg) was prepared according to
formulation 3 (see Table 1) using test arrangement 7. Carbon
black/demoulding agent masterbatch granules according to Table 1,
which were prepared as described under A.2, were added as the
carbon black component.
For the preparation of the compound, a premix was first prepared
from components b (carbon black component), g (additives) and f3
given in Table 1 in the mentioned amounts. Preparation of the
premix and compounding of the moulding composition were carried out
as described in Example 1.
The process parameters of the extruder and the number, measured as
described above, of surface defects, based on one square
centimeter, and the measured notched impact strength according to
ISO 180/1A are listed in Table 4 under Example 36.
Example 37
According to the Invention
An elastomer-containing polycarbonate blend having a melt volume
flow rate (MVR) of 27 cm.sup.3/10 min (measured according to ISO
1133 at 260.degree. C. and 5 kg) was prepared according to
formulation 2 (see Table 1) using test arrangement 7. Carbon
black/demoulding agent masterbatch granules according to Table 1,
which were prepared as described under A.2, were added as the
carbon black component.
For the preparation of the compound, a premix was first prepared
from components b (carbon black component), g (additives) and f3
given in Table 1 in the mentioned amounts. Preparation of the
premix and compounding of the moulding composition were carried out
as described in Example 1.
The process parameters of the extruder and the number, measured as
described above, of surface defects, based on one square
centimeter, and the measured notched impact strength according to
ISO 180/1A are listed in Table 4 under Example 37.
A comparison of Examples 2, 36 and 37 according to the invention
with Comparison Example 1 shows that, when the carbon
black/demoulding agent masterbatches prepared in a co-kneader with
different process parameters and test arrangements are used, the
number of surface defects is markedly smaller and the notched
impact strength at 23.degree. C. and at 0.degree. C. is markedly
higher than when the carbon black powder is used.
TABLE-US-00001 TABLE 1 (all amounts in wt. %) 95 1 2 3 4 5 6 7 8
all amounts in wt % Comp. Invention Invention Invention Invention
Invention Invention Inven- tion a a1 14.14 a2 42.1 73.3 73.3 73.3
73.3 73.34 73.3 73.3 a3 a4 a5 a6 a7 a8 a9 16.9 B B1 1.49 B2 1.49 B3
1.49 B4 1.49 B5 1.29 B6 1.49 B7 1.15 B8 B9 B10 B11 B12 B13 B14 B15
B16 b1 0.75 b3 b4 c c1 0.73 0.16 0.34 d d1 d2 f f1 f2 f3 6.89 6.8
6.8 6.8 6.8 6.8 6.8 6.8 f4 f5 f6 f7 17.6 17.52 17.52 17.52 17.52
17.52 17.52 17.52 g g1 g2 g3 0.89 0.89 0.89 0.89 0.89 0.89 0.89
0.89 g4 g5 Formulation Component 9 10 11 12 13 14 15 16 17 all
amounts in wt % Invention Invention Invention Invention Invention
Invention Invention C- omp. Comp. a a1 a2 73.3 73.21 73.34 73.44
73.21 73.21 73.21 62.58 73.3 a3 a4 a5 a6 a7 a8 a9 4.92 B B1 B2 B3
B4 B5 B6 B7 B8 1.49 B9 1.9 B10 1.25 B11 1.67 B12 1.9 B13 1.9 B14
1.9 B15 6.53 B16 1.94 b1 b3 b4 c c1 0.2 0.73 0.72 d d1 d2 f f1 f2
f3 6.8 6.8 6.8 6.8 6.8 6.8 6.8 6.82 6.15 f4 f5 f6 f7 17.52 17.2
17.52 17.2 17.2 17.2 17.2 17.54 17 g g1 g2 g3 0.89 0.89 0.89 0.89
0.89 0.89 0.89 0.88 0.89 g4 g5 Formulation Component 18 19 20 21 22
23 24 25 all amount in wt % Comp. acc. to inv. Comp. acc. to inv.
Comp. acc. to inv. Comp. acc. to inv. a a1 22 21.9 a2 42.2 42.2 a3
59.89 59.89 a4 95 95 a5 95 95 a6 a7 a8 a9 4.44 4.44 4.44 4.44 B B1
B2 B3 1.5 1 0.32 B4 B5 0.28 B6 B7 B8 B9 B10 B11 B12 B13 B14 B15 B16
b1 0.75 0.5 0.16 0.16 b3 b4 c c1 0.75 0.4 0.4 0.24 0.4 0.28 d d1 d2
f f1 17.1 17.1 f2 8.84 8.84 15.8 15.8 f3 f4 2.95 2.95 3 3 f5 f6 f7
9.4 9.4 g g1 14.9 14.9 g2 0.8 0.8 g3 0.32 0.32 0.4 0.4 0 0 0 0 g4
g5 Formulation Component 26 27 28 29 30 31 all amount in wt % Comp.
acc. to inv. Comp. acc. to inv. Comp. acc. to inv. a a1 36 a2 95.6
a3 62.4 a4 a5 a6 95 95 a7 95 95 a8 3.82 1.04 a9 4.54 4.54 4.84 4.72
B B1 B2 B3 B4 B5 0.28 0.28 0.28 B6 B7 B8 B9 B10 B11 B12 B13 B14 B15
B16 b1 0.16 0.16 0.16 b3 b4 c c1 0.4 0.28 0.3 0.18 d d1 d2 f f1 f2
f3 f4 f5 f6 f7 g g1 g2 g3 0.02 0 0 0 0 0 g4 g5 Formulation
Component 32 33 34 35 36 all amount in wt % Comp. Comp. acc. to
inv. Comp. acc. to inv. a a1 a2 48.61 48.76 48.47 a3 74.19 75.11 a4
a5 a6 a7 a8 1.04 0.94 1.03 a9 B B1 B2 B3 1.8 B4 B5 0.51 B6 B7 B8
B9
B10 B11 B12 B13 B14 B15 B16 0.59 b1 0.3 0.9 b3 0.25 0.25 b4 0.057
0.057 c c1 0.4 0.2 0.18 0.73 d d1 31.84 31.75 31.75 d2 0.561 0.5525
0.765 f f1 f2 f3 f4 f5 14.95 14.91 14.95 f6 8.77 8.75 f7 13.21
13.14 g g1 g2 g3 0.299 0.2975 0.347 0.89 0.89 g4 2 2 2 g5 1
TABLE-US-00002 TABLE 2 Heating temperatures 1st 2nd Housing Carbon
black/ housing housing single- Co- demoulding Test Through- half
co- half co- shaft Nozzle kneader agent master- arrange- Formula-
Carbon black put Speed Power SME kneader kneader extruder head
shaft batch no. ment tion metering site kg/h min-1 kW kWh/kg
.degree. C. .degree. C. .degree. C. .degree. C. .degree. C. B1 1
50% b1 Feed hopper 1 9 190 3.4 0.378 30 30 40 95 30 50% c1 B2 2 50%
b1 Feed hopper 1 12 190 3.3 0.275 90 60 35 130 35 50% c1 B3 3 50%
b1 Feed hopper 1: 32% 20 250 3.8 0.190 60 35 75 110 35 50% c1 Feed
hopper 7: 18% B4 3 50% b2 Feed hopper 1: 20% 12 250 2.3 0.192 60 35
75 110 35 50% c1 Feed hopper 7: 30%
TABLE-US-00003 TABLE 3 Carbon black/ demoulding Test Through- Spec.
Heating temperatures of the housing parts: agent master- arrange-
Formula- Carbon black put Speed power 9 10 11 batch no. ment tion
metering site kg/h min.sup.-1 kWh/kg .degree. C. .degree. C.
.degree. C. B8 4 50% b1 Feed hopper 8: 25% 25 200 0.084 30 60 65
50% c1 Housing part 15: 25% B9 4 40% b1 Feed hopper 8: 10% 25 300
0.0096 30 60 65 60% c1 Housing part 15: 30% B10 4 60% b1 Feed
hopper 8: 15% 25 200 0.248 30 60 65 40% c1 Housing part 15: 45% B11
4 45% b1 Feed hopper 8: 10% 25 300 0.037 30 60 65 55% c1 Housing
part 15: 35% B12 4 40% b1 Feed hopper 8: 20% 25 200 0.032 30 60 65
60% c3 Housing part 15: 20% B13 4 40% b1 Feed hopper 8: 20% 25 200
0.073 30 60 65 60% c2 Housing part 15: 20% B14 4 40% b1 Feed hopper
8: 20% 25 200 0.073 30 60 65 60% c4 Housing part 15: 20% Heating
temperatures of the housing parts: Carbon black/ Nozzle demoulding
(not agent master- 12 13 14 15 16 17 18 19 shown) batch no.
.degree. C. .degree. C. .degree. C. .degree. C. .degree. C.
.degree. C. .degree. C. .degree.C. .degree. C. B8 65 65 65 70 50 50
50 35 110 B9 65 65 65 70 50 50 50 35 110 B10 65 65 65 70 50 50 50
35 130 B11 65 65 65 70 50 50 50 35 110 B12 65 65 65 70 50 50 50 35
110 B13 65 65 65 70 50 50 50 35 130 B14 65 65 65 70 50 50 50 35
115
TABLE-US-00004 TABLE 4 Surface defects Notched impact Notched
impact Test Through- per cm.sup.2 strength strength Formula-
arrange- put Speed SME Mean of 3 at 23.degree. C. at 0.degree. C.
Example tion ment kg/h 1/min kWh/kg sheets kJ/m.sup.2 kJ/m.sup.2 1
Comparison 1 7 103 400 0.129 199 46.9 13.75 2 Invention 4 7 97 400
0.137 19 50.94 15.09 3 Comparison 18 7 92 400 0.145 53 4 Invention
19 7 92 400 0.145 24 5 Comparison 20 8 99 600 0.145 17 12.77 6
Invention 21 8 98 600 0.147 11 13.06 7 Comparison 22 7 62 350 0.188
12 8 Invention 23 7 64 350 0.182 9 9 Comparison 24 7 62 350 0.188 5
10 Invention 25 7 62 350 0.188 4 11 Comparison 28 7 52 350 0.224
257 12 Invention 29 7 52 350 0.224 34 13 Comparison 30 7 58 350
0.201 60 14 Invention 31 7 57 350 0.204 31 15 Comparison 35 9 20
400 0.247 16 Invention 36 9 20 400 0.24 17 Comparison 17 7 73 400
0.131 34 18 Comparison 16 7 73 400 0.131 63 19 Invention 4 7 75 400
0.133 18 20 Comparison 32 10 3100 187 0.131 2191 21 Comparison 33
10 3091 175 0.124 1122 22 Invention 34 10 3092 188 0.131 446 23
Comparison 26 11 2975 493 0.141 247 24 Invention 27 11 3003 485
0.132 11 25 Invention 10 7 95 400 0.14 6 26 Invention 12 7 95 400
0.14 6 27 Invention 9 7 90 400 0.148 10 28 Invention 6 7 95 400
0.14 5 29 Invention 11 7 95 400 0.14 5 30 Invention 8 7 90 400
0.148 21 31 Invention 7 7 90 400 0.148 11 32 Invention 13 7 90 400
0.148 7 33 Invention 14 7 95 400 0.14 48 34 Invention 15 7 95 400
0.14 6 35 Invention 5 7 97 400 0.137 23 56.2 19.22 36 Invention 3 7
97 400 0.137 19 48.3 16.16 37 Invention 2 7 97 400 0.137 17 52.73
15.93
* * * * *