Plastic molding composition containing a filler

In the case of polyolefins filled with alkaline earth metal carbonates, a very good compatibility of the hydrophilic filler and the hydrophobic polymer matrix is reached when using as adhesion promoters certain organo-phosphorus compounds. As a result, improved mechanical properties are obtained with the articles made of plastic material that has been prepared from such polyolefin molding compositions.

The present invention relates to a plastic molding composition containing a 
filler. 
As has already been described, the mechanical, electrical and thermal 
properties of plastic materials can be improved by adding inorganic 
fillers. However, due to their hydrophilic properties, these fillers show 
only a low compatibility with the mostly hydrophobic polymers. In the case 
of polymers filled with inorganic substances, this leads to a 
deterioration of some mechanical properties. 
It has already been proposed to treat natural calcium carbonates with 
surface-active substances in order to improve their dispersibility in 
plastic materials. These substances comprise saturated and unsaturated 
fatty acids having a medium or high molecular weight, for example, butyric 
acid, lauric acid, oleic acid, and stearic acid (cf. German Patent 
Specification No. 958 830). 
It has been known to use a calcium carbonate treated with stearic acid as 
impact resistant component in the preparation of impact resistant 
unplastiziced shaped articles on the basis of polyvinyl chloride (cf. 
German Auslegeschrift No. 1 469 886). 
It has also been proposed to combine calcium carbonate with compounds which 
contain an ethylene bond in the molecule and with free radical forming 
agents (cf. German Offenlegungsschriften Nos. 1 794 310 and 20 61 180). 
Finally it has also been described to react alkaline earth metal carbonates 
with at least one unsaturated carboxylic acid, while stirring, in the 
absence of liquid water in the pulverulent inorganic material. In this 
process, free radical forming agents may be present (cf. German 
Auslegeschrift No. 22 62 126). 
It has become evident, however, that the improvements of the mechanical 
properties obtained by using modified alkaline earth metal carbonates are 
not yet sufficient, especially for polyolefins. 
It has now been found that a very good compatibility between the 
hydrophilic filler and the hydrophobic polymer matrix is reached, which 
results in improved mechanical properties of plastic material articles 
prepared thereof, when using an adhesion promoter certain 
organo-phosphorus compounds. 
The present invention provides a plastic molding composition containing a 
filler, which composition consists of 
from 20 to 90 parts by weight of a polyolefin, 
from 10 to 80 parts by weight of an alkaline earth metal carbonate, 
common additives as well as from 0.1 to 10% by weight, calculated on the 
filler, of an adhesion promoter, said adhesion promoter being an 
organo-phosphorus compound of the formula 
##STR1## 
in which R.sup.1 is an alkyl radical having from 1 to 18 carbon atoms, an 
alkenyl radical of from 2 to 18 carbon atoms, an aralkyl radical of from 7 
to 13 carbon atoms, whose alkyl chain has from 1 to 3 carbon atoms, or an 
aralkenyl radical of from 8 to 13 carbon atoms, whose alkenyl chain has 2 
or 3 carbon atoms, and R.sup.2 and R.sup.3, which are identical or 
different, represent hydrogen, an alkyl radical of from 1 to 8 carbon 
atoms, an aryl radical of from 6 to 10 carbon atoms, an aralkyl radical of 
from 7 to 13 carbon atoms, whose alkyl chain has from 1 to 3 carbon atoms, 
or an alkenyl radical of from 3 to 5 carbon atoms. 
The organo-phosphorus compounds of the formula (I) to be used according to 
the invention are phosphonic acids and the esters thereof. In formula (I) 
R.sup.1 is an alkyl radical of from 1 to 18, preferably 3 to 8, especially 
2 to 6 carbon atoms. The alkyl radical may be straight-chained or branched 
or cyclic. R.sup.1 represents also an alkenyl radical of from 2 to 18, 
preferably 2 to 12 carbon atoms, or an aralkyl radical of from 7 to 13, 
preferably 7 to 10, especially 7 to 9 carbon atoms, whose alkyl chain has 
from 1 to 3, preferably 1 or 2 carbon atoms, or an aralkenyl radical of 
from 8 to 13, preferably 8 to 10, especially 8 or 9 carbon atoms, whose 
alkenyl chain has 2 or 3 carbon atoms. The aromatic radical is a 
carbocyclic nucleus having 6 or 10 cyclic carbon atoms which may carry 
lateral chains. R.sup.2 and R.sup.3 are identical or different and each 
represent hydrogen, an unbranched or branched or cyclic alkyl radical 
having from 1 to 8, preferably 2 to 8 carbon atoms, an aryl radical of 
from 6 to 10, preferably 6 to 8 carbon atoms, an aralkyl radical of from 7 
to 13, preferably 7 to 10 carbon atoms, whose alkyl chain has from 1 to 3, 
preferably 1 or 2 carbon atoms, or an alkenyl radical of from 3 to 5, 
preferably 3 or 4 carbon atoms. Aromatic radicals are preferably 
carbocyclic nuclei with 6 or 10 cyclic carbon atoms which may carry 
lateral chains. 
The phosphonic acids and phosphonic acid esters to be used in accordance 
with the invention may be prepared according to known methods. 
Thus, for example, the phosphonic acids may be prepared from their tetra- 
or dihalides by a reaction with water, by saponification of the 
corresponding esters, by the disproportionation of phosphonous acids or by 
the addition of phosphorous acid to olefinic double bonds; the phosphonic 
acid esters may be prepared by reacting the phosphonic acid-tetra- or 
-dihalides with alcohols or from esters of phosphorous acid with alkyl 
halides (Kosolapoff, Organophosphorous Compounds, Wiley and Sons, New 
York, 1950; Houben-Weyl, vol. XXI/1, Thieme Verlag Stuttgart). 
Suitable phosphonic acids are, for example, methane-phosphonic acid, 
ethane-phosphonic acid, propane-phosphonic acid, butane-phosphonic acid, 
n-hexane-phosphonic acid, cyclohexane-phosphonic acid, 
2,3-dimethyl-butane-phosphonic acid, octane-phosphonic acid, 
decane-phosphonic acid, dodecane-phosphonic acid, octadecane-phosphonic 
acid, phenylmethane-phosphonic acid, 2-phenylethane-phosphonic acid-1, 
vinyl-phosphonic acid, allyl-phosphonic acid, 1-phenylvinyl-phosphonic 
acid-1, 2-phenylvinyl-phosphonic acid-1, 
2,4-dimethyl-4-methyl-pentane-phosphonic acid, 
dimethyl-2-methylpropane-phosphonic acid and 
2,4-dimethyl-butane-phosphonic acid. There are preferably used 
vinyl-phosphonic acid, propane-phosphonic acid, hexane-phosphonic acid, 
octane-phosphonic acid, dodecane-phosphonic acid, 
2,4-dimethyl-4-methyl-pentane-phosphonic acid, 
dimethyl-2-methylpropane-phosphonic acid and 
2,4-dimethyl-butane-phosphonic acid. 
Suitable phosphonic acid esters are, for example, methane-phosphonic 
acid-diethyl ether, ethane-phosphonic acid-diethyl ester, 
ethane-phosphonic acid-dibutyl ester, butane-phosphonic acid-dibutyl 
ester, n-hexane-phosphonic acid-diethyl ester, n-hexane-phosphonic 
acid-diphenyl ester, octane-phosphonic acid-diethyl ester, 
dodecane-phosphonic acid dimethyl ester, octadecane-phosphonic 
acid-diethyl ester, vinyl-phosphonic acid-diethyl ester, vinyl-phosphonic 
acid-di-(2-ethyl-hexyl)-ester, vinyl-phosphonic acid-dioctyl ester, 
vinyl-phosphonic acid-diallyl ester, allyl-phosphonic acid-diallyl ester, 
allyl-phosphonic acid-dimethallyl ester, phenylmethane-phosphonic 
acid-monoethyl ester, methane-phosphonic acid-ethylhexyl ester. Preference 
is given to butane-phosphonic acid-dibutyl ester, vinyl-phosphonic 
acid-diallyl ester, vinyl-phosphonic acid-dimethyl ester and vinyl 
phosphonic acid-dioctyl ester. 
The phosphonic acids and phosphonic acid esters to be used according to the 
invention are added to the molding composition in an amount of from 0.1 to 
10% by weight, preferably from 0.5 to 2% by weight, calculated on the 
filler. There may also be used mixtures of different phosphonic acids or 
phosphonic acid esters or mixtures of phosphonic acids with phosphonic 
acid esters. 
The filler may be a natural or synthetic, i.e. precipitated alkaline earth 
metal carbonate. Suitable carbonates are, for example, limestone powder, 
chalk, precipitated calcium carbonate, natural magnesite, natural 
hydromagnesite, synthetic basic magnesium carbonate, calcium-magnesium 
carbonate, dolomite. Preference is given to the calcium carbonates. The 
alkaline earth metal carbonates to be used according to the invention have 
an average particle diameter of from 0.1 to 50 .mu.m, preferably from 1 to 
10 .mu.m. There may also be used mixtures of different alkaline earth 
metal carbonates. 
The incorporation of the phosphonic acid or the phosphonic acid ester into 
the molding composition may be effected according to various methods. 
Thus, for example, the filler may be suspended in an organic solvent; as 
solvents there may be used alcohols, such as methanol, ethanol, butanol; 
hydrocarbons, such as hexane, benzene, toluene; ethers, such as diethyl 
ether, di-isopropyl ether, or ketones, such as acetone or diethyl ketone. 
It is also possible to add the adhesion promoter directly or dissolved in 
a suitable solvent, to stir the mixture thoroughly at room temperature or 
elevated temperature, to eliminate the solvent by distillation and to dry 
the residue. The filler may also be thoroughly mixed with the adhesion 
promoter in a mixer at room temperature or at elevated temperature, the 
temperature optionally being above the melting point of the adhesion 
promoter. 
If the adhesion promoter is liquid, it may be added dropwise to the filler 
directly or diluted with an appropriate solvent in a high-speed mixer, or 
may be sprayed in the form of a mist by means of a spray nozzle onto the 
filler. In this way it is possible to apply also solid adhesion promoters 
dissolved in a suitable solvent onto the filler. 
Alternatively, the adhesion promoter may be mixed with the polymer in a 
mixer and the untreated filler can subsequently be added, or all three 
components, i.e. the polymer, the filler and the adhesion promoter, may be 
mixed simultaneously. This simultaneous mixing may be carried out in a 
pre-mixer, but also in a granulating extruder. 
According to a preferred method the filler is first treated with the 
adhesion promoter. 
The filler is admixed to the polymer in an amount of from 10 to 80% by 
weight, preferably 30 to 70% by weight. 
For the plastic molding compositions of the invention there are suitable as 
basic polymers 1-olefin-homo- and copolymers, for example polyethylene of 
high density and low density, polypropylene, polybutene-1, 
poly-(4-methyl)-pentene-1, olefin copolymers, such as ethylene-propylene 
copolymers and ethylene-butene copolymers, mixtures of these polymers and 
mixtures of these polymers with caoutchouc-like polymers. Polyethylene is 
particularly preferred. 
The content of polymer in the molding composition is from 20 to 90, 
preferably from 30 to 70% by weight. 
The molding compositions of the invention may contain the common additives 
which facilitate the further processing and improve the physical 
properties. There are to be mentioned light and heat stabilizers, 
antioxidants, antistatic agents, etc. as well as coloring pigments and 
flameproofing agents. The former group is generally contained in the 
molding compositions in an amount of from 0.01 to 5% by weight, calculated 
on the amount of polymer and the filler. The coloring pigments and 
flameproofing agents are used in an amount which corresponds to the 
requirements. 
An effective stabilizer combination for poly-1-olefins, such as high, 
medium and low pressure polymers of C.sub.2 to C.sub.4 -1-olefins, 
especially polyethylene and polypropylene, or for copolymers of such 
1-olefins may for example consist--each calculated on 100 parts by weight 
of polymer--of from 0.05 to 4 parts by weight of a phenolic stabilizer, 
optionally from 0.01 to 4 parts by weight of a sulfur-containing 
co-stabilizer, and optionally from 0.01 to 3 parts by weight of a basic or 
neutral metal soap, for example calcium stearate or zinc stearate, as well 
as optionally from 0.1 to 4 parts by weight of a phosphite, and optionally 
from 0.01 to 4 parts by weight of a known UV-stabilizer from the group of 
alkoxyhydroxy-benzophenones, hydroxyphenyl-benzotriazoles, 
benzylidene-malonic acid-mononitrile esters or the so-called quenchers 
(for example nickel chelates). 
If an olefinically unsaturated phosphonic acid or a corresponding ester is 
used as modifying agent, a polymerization initiator, for example, benzoyl 
peroxide, dicumyl peroxide, tert.-butyl-hydroperoxide, 
tert.-butyl-peroctoate, azobis-isobutyronitrile, may be added in an amount 
of from 0.01 to 1% by weight, calculated on the amount of unsaturated 
phosphonic acid or phosphonic acid ester. 
Shaped articles which have been manufactured from the thermoplastic molding 
composition of the invention show a very good impact strength and tensile 
impact strength, which makes them especially suitable for the production 
of technical articles. 
Another advantage of the adhesion promoters to be used according to the 
invention is to be seen in the fact that they have a favorable influence 
on the flow properties of the polymer melt in the injection molding 
process and facilitate for example the charging of the mold when 
manufacturing complicated injection molded pieces.

The following Examples serve to illustrate the present invention in detail. 
EXAMPLE 1 
450 Parts of calcium carbonate of the calcite type having an average 
particle diameter of 5 .mu.m and a specific surface according to the BET 
method (Brunauer, Emmet, Teller, J.Am.Chem.Soc. 60, 309) of 1 m.sup.2 /g 
are suspended in 2000 parts of acetone. 50 Parts of vinyl-phosphonic acid 
are added dropwise, while stirring thoroughly, within 30 minutes. The 
suspension is stirred for 2 hours at room temperature, subsequently the 
acetone is distilled off in vacuo and the residue is dried at 40.degree. 
C. in the vacuum drying cabinet. 
450 Parts of the calcium carbonate thus treated are thoroughy mixed with 
1050 parts of polyethylene (density of 0.96 g/cm.sup.3, melting index of 
23 g/10 min., containing 0.42% by weight of a phenolic stabilizer and 2.5% 
by weight of a sulfur-containing co-stabilizer) in a plowshare mixer. The 
mixture obtained is extruded to a strand in a double screw extruder, which 
strand is then granulated in a cutting machine. By means of an injection 
molding machine, test samples are prepared from the granules. 
In a comparison example, 450 parts of untreated calcium carbonate are mixed 
in the same manner with 1050 parts of polyethylene. The mixture is further 
processed, as has been described above. 
The properties of the test samples have been indicated in Table I, 1/2 
standard rod serving as test sample. 
The elongation and tensile strength are determined according to DIN 53 455, 
the impact strength according to DIN 53 453 (jaw distance 30 mm, 
transverse position), the tensile impact strength according to DIN 53 448, 
the ball indentation hardness according to DIN 52 456, and the E-module 
according to DIN 53 457. 
TABLE I: 
__________________________________________________________________________ 
tensile ball in- 
elon- 
tensile 
impact 
impact 
E-module 
dentation 
adhesion 
gation 
strength 
strength 
strength 
-10.sup.3 
hardness 
promoter 
% N/mm.sup.2 
mJ/mm.sup.2 
mJ/mm.sup.2 
N/mm.sup.2 
N/mm.sup.2 
__________________________________________________________________________ 
-- 22 23 65 80 0.7 43 
vinyl- 
30 28 without 
130 0.64 44 
phosphonic breaking 
acid 
__________________________________________________________________________ 
EXAMPLES 2 to 14 
The same calcium carbonate as in Example 1 is treated with different 
phosphonic acids and/or phosphonic acid esters in different 
concentrations--calculated on the amounts of calcium carbonate. 300 Parts 
of the calcium carbonate thus treated are mixed with 700 parts of also the 
same polyethylene, and the mixture is processed as has been described in 
Example 1. The properties of the test samples have been specified in Table 
II. 
EXAMPLE 15 
500 Parts of calcium carbonate of the calcite type having an average 
particle diameter of 5 .mu.m and a specific surface (BET) of 1 m.sup.2 /g 
and 7.5 parts of octane-phosphonic acid are mixed in a high-speed mixer at 
800 rpm at 80.degree. C. for 30 minutes. 
450 Parts of the calcium carbonate thus treated are mixed thoroughly with 
1050 parts of polyethylene (density of 0.96 g/cm.sup.3, melting index of 
23 g/10 min) in a plow-share mixer. The further processing of the mixture 
is effected as has been described in Example 1. The properties of the test 
samples have been specified in Table III. 
TABLE II 
__________________________________________________________________________ 
Adhesion promoter 
##STR2## 
elon- tensile 
ga- 
tensile 
impact 
impact 
tion 
strength 
strength 
strength 
R.sup.1 R.sup.2,R.sup.3 
content 
% N/mm.sup.2 
mJ/mm.sup.2 
mJ/mm.sup.2 
__________________________________________________________________________ 
C.sub.3 H.sub.7 
H 1% 44 22 w/o b..sup.(3) 
110 
C.sub.6 H.sub.13 
H 0.8% 
42 24 w/o b. 
110 
C.sub.8 H.sub.17 
H 1.5% 
40 23 w/o b. 
110 
##STR3## H 0.7% 
30 24 w/o b. 
110 
C.sub.12 H.sub.25 
H 5% 40 24 w/o b. 
100 
C.sub.12 H.sub.25 
H 1.5% 
44 23 w/o b. 
120 
C.sub.18 H.sub.37 
H.sup.(1) 0.7% 
46 26 w/o b. 
120 
CH.sub.2CH CH.sub.2CHCH.sub.2 
5% 32 30 w/o b. 
130 
CH.sub.2CH CH.sub.2CHCH.sub.2 
8% 29 27 w/o b. 
130 
C.sub.12 H.sub.25 
H 7% 40 24 w/o b. 
110 
CH.sub.2CH CH.sub.3.sup.(2) 
6.5% 
40 26 w/o b. 
130 
CH.sub.2CH C.sub.8 H.sub.17 
1% 38 24 w/o b. 
130 
##STR4## H 3% 28 26 120 110 
__________________________________________________________________________ 
.sup.(1) in methanol 
.sup.(2) in diethyl ether 
.sup.(3) w/o b. = withoutbreaking 
EXAMPLE 16 
Example 15 is repeated, with the difference that instead of 
octane-phosphonic acid there are used 3 parts of dodecane-phosphonic acid 
for the modification of the calcium carbonate. The properties of the test 
samples have been specified in Table III. 
EXAMPLE 17 
By means of a spray nozzle, a solution of 5 parts of octadecane phosphonic 
acid in 50 parts of acetone is sprayed within 30 minutes onto 500 parts of 
calcium carbonate of the calcite type having an average particle diameter 
of 5 .mu.m and a specific surface (BET) of 1 m.sup.2 /g in a high-speed 
mixer at 1200 rpm. 
450 Parts of the calcium carbonate thus treated are thoroughly mixed with 
1050 parts of polyethylene (density of 0.96 g/cm.sup.3, melting index of 
23 g/10 min., containing 0.42% by weight of a phenolic stabilizer and 2.5% 
by weight of a sulfur-containing co-stabilizer) in a plowshare mixer. The 
further processing of the mixture is effected as has been described in 
Example 1. The properties of the test samples have been specified in Table 
III. 
EXAMPLE 18 
Example 17 is repeated, with the difference that instead of 
octadecane-phosphonic acid there are used 5 parts of vinylphosphonic 
acid-bis-(2-ethyl-hexyl)-ester without solvent. The further processing of 
the mixture is effected as has been described in Example 1. The properties 
of the test samples have been specified in Table III. 
EXAMPLE 19 
Example 17 is repeated, with the difference that instead of 
octadecane-phosphonic acid there are used 10 parts of vinyl-phosphonic 
acid. The further processing of the mixture is effected as has been 
described in Example 1. The properties of the test samples have been 
indicated in Table III. In accordance with Example 15, a mixture of 
untreated calcium carbonate and polyethylene is prepared as comparison 
sample. 
TABLE III 
______________________________________ 
tensile 
elonga- tensile impact impact 
tion strength strength strength 
Example % N/mm.sup.2 
mJ/mm.sup.2 
mJ/mm.sup.2 
______________________________________ 
compa- 23 22 68 80 
rison 
15 39 21 w/o b. 110 
16 46 21 w/o b. 110 
17 46 26 w/o b. 120 
18 40 24 w/o b. 130 
19 42 26 w/o b. 130 
______________________________________ 
EXAMPLE 20 
500 Parts of calcium carbonate of the calcite type having an average 
particle diameter of 1.5 .mu.m and a specific surface (BET) of 7 m.sup.2 
/g are suspended in 2500 parts of n-hexane. Within 30 minutes, 12.5 parts 
of vinyl-phosphonic acid are added dropwise, while stirring thoroughly. 
The suspension is continued to be stirred for 3 hours at room temperature; 
subsequently the hexane is distilled off in vacuo, and the residue is 
dried at 40.degree. C. in the vacuum drying cabinet. 450 Parts of the 
calcium carbonate thus treated are mixed thoroughly with 1050 parts of 
polyethylene (density of 0.96 g/cm.sup.3, melting index of 23 g/10 min., 
containing 0.42% by weight of a phenolic stabilizer and 2.5% by weight of 
a sulfur-containing co-stabilizer) in a plowshare mixer. The mixture 
obtained is extruded in a double screw extruder to give a strand which is 
then granulated in a cutting machine. By means of an injection molding 
machine, test samples are prepared from the granules. 
In a comparative example 450 parts of untreated calcium carbonate are mixed 
with 1050 parts of polyethylene in the same manner and are then further 
processed. 
The properties of the test samples have been specified in Table IV. 
EXAMPLE 21 
500 Parts of precipitated calcium carbonate having an average particle 
diameter of 0.2 .mu.m and a specific surface (BET) of 9 m.sup.2 /g are 
suspended in 2500 parts of acetone. 5 Parts of vinyl-phosphonic acid are 
added dropwise within 30 minutes, while stirring thoroughly. 
The working up, mixing with polyethylene and testing are effected as has 
been described in Example 20. 
In this case, too, a comparison pattern is prepared with unmodified 
precipitated calcium carbonate. 
The properties of the test samples have been specified in Table IV. 
EXAMPLE 22 
Example 21 is repeated with the proviso that instead of acetone there is 
used methanol and instead of vinyl-phosphonic acid use is made of 
octane-phosphonic acid as modifying agent for precipitated calcium 
carbonate. The properties of the test samples have been indicated in Table 
IV. 
TABLE IV 
______________________________________ 
tensile 
elonga- tensile impact impact 
tion strength strength strength 
Example % N/mm.sup.2 
mJ/mm.sup.2 
mJ/mm.sup.2 
______________________________________ 
compa- 
rison 
with 20 21 24 47 80 
20 42 24 w/o b. 100 
compa- 
rison 19 25 40 90 
with 21, 22 
21 38 26 w/o b. 110 
22 40 24 w/o b. 110 
______________________________________ 
EXAMPLE 23 
In a high-speed mixer at 1200 rpm a solution of 4.7 parts of 
vinyl-phosphonic acid in 4.7 parts of water is sprayed from a spray nozzle 
within 20 minutes onto 1100 parts of polyethylene having a density of 0.96 
g/cm.sup.3 and a melting index of 23 g/10 min. 
1050 Parts of the polyethylene thus treated are thoroughly mixed in a 
plowshare mixer with 450 parts of calcium carbonate (average particle 
diameter 5 .mu.m, specific surface 1 m.sup.2 /g). 
The further processing of the mixture is effected as has been described in 
Example 1. The properties of the test samples have been specified in Table 
V. 
EXAMPLE 24 
Example 23 is repeated, in which process 0.04 part of 
tert.-butyl-hydroperoxide is additionally added into the high-speed mixer. 
The further processing of the mixture is effected as has been described in 
Example 1. The properties of the test samples have been specified in Table 
V. 
EXAMPLE 25 
1100 Parts of polyethylene (density of 0.96 g/cm.sup.3, melting index of 23 
g/10 min., stabilized as in Example 1) and 7 parts of octane-phosphonic 
acid are mixed for 20 minutes in a high-speed mixer at 80.degree. C. 
1050 Parts of the polyethylene thus treated are mixed thoroughly in a 
plowshare mixer with 450 parts of calcium carbonate (average particle 
diameter 5 .mu.m, specific surface 1 m.sup.2 /g). 
The further processing of the mixture is effected as has been described in 
Example 1. The properties of the test samples have been described in Table 
V. 
EXAMPLE 26 
Example 25 is repeated with the modification that instead of 
octane-phosphonic acid there is used dodecanephosphonic acid. The 
properties of the test samples have been indicated in Table V. 
EXAMPLE 27 
At 80.degree. C., 1050 parts of polyethylene (density of 0.96 g/cm.sup.3, 
melting index of 23 g/10 min., stabilized as in Example 1), 450 parts of 
calcium carbonate (average particle diameter 5 .mu.m, specific surface 1 
m.sup.2 /g) and 4.5 parts of octane-phosphonic acid are mixed in a 
high-speed mixer for 30 minutes. The extrusion and testing are effected as 
has been described in Example 1. 
The properties of the test samples have been specified in Table V. 
TABLE V 
______________________________________ 
tensile 
elonga- tensile impact impact 
tion strength strength strength 
Example % N/mm.sup.2 
mJ/mm.sup.2 
mJ/mm.sup.2 
______________________________________ 
23 30 28 w/o b. 110 
24 30 28 w/o b. 110 
25 42 26 w/o b. 130 
26 38 22 w/o b. 130 
27 42 28 w/o b. 130 
______________________________________ 
EXAMPLES 28 to 35 
Polyolefin molding compositions are manufactured from 70% by weight of 
polyethylene (density of 0.96 g/cm.sup.3, melting index of 23 g/10 min., 
stabilized as in Example 1) and 30% by weight of calcium carbonate 
(average particle size 5 .mu.m, specific surface 1 m.sup.2 /g) which has 
been treated with different modification agents according to Example 1. 
The test samples are tested for their impact strength. The results are 
given in Table IV. 
TABLE VI 
______________________________________ 
impact strength 
adhesion promoter mJ/mm.sup.2 
Ex. kind amount.sup.(1) 
mean value 
w/o b. 
______________________________________ 
28 vinyl-phosphonic acid 
1% 100% 
29 vinyl-phosphonic acid 
1% 100% 
+ DCP.sup.(2) 
30 octane-phosphonic acid 
1% 100% 
31 acrylic acid 1% 30% : 95 
70% 
32 acrylic acid + DCP.sup.(2) 
1% 30% : 100 
70% 
33 maleic acid 1% 35% : 70 
65% 
34 maleic acid + DCP.sup.(2) 
1% 35% : 110 
65% 
35 stearic acid 3% 70% : 75 
30% 
______________________________________ 
.sup.(1) % by weight, calculated on the amount of calcium 
.sup.(2) dicumyl peroxide; 0.1%, calculated on the adhesion promoter 
EXAMPLE 36 
500 Parts of calcium carbonate having an average particle diameter of 2.5 
.mu.m and a spefic surface (BET) of 2 m.sup.2 /g are suspended in 2000 
parts of acetone. 
0.5 Part of vinyl-phosphonic acid is added, while stirring thoroughly. The 
suspension is continued to be stirred for 3 hours at room temperature, 
subsequently the acetone is distilled off in vacuo, and the residue is 
dried at 40.degree. C. in the vacuum drying cabinet. 
450 Parts of the calcium carbonate thus treated are thoroughly mixed with 
1050 parts of polyethylene (density of 0.96 g/cm.sup.3, melting index of 
23 g/10 min., containing 0.42% by weight of a phenolic stabilizer and 2.5% 
by weight of a sulfur-containing co-stabilizer) in a plow-share mixer. 
The preparation of the test samples and their testing are effected as has 
been described in Example 1. 
For reasons of comparison, 450 parts of untreated calcium carbonate are 
mixed with 1050 parts of polyethylene in the same manner and are further 
processed, as has been described above. 
The properties of the test samples are shown in Table VII. 
EXAMPLE 37 
At 80.degree. C., 500 parts of calcium carbonate having an average particle 
diameter of 2.5 .mu.m and a specific surface (BET) of 2 m.sup.2 /g and 2.5 
parts of octane-phosphonic acid are mixed for 20 minutes in a high-speed 
mixer at 1200 rpm. 450 Parts of the calcium carbonate thus treated are 
thoroughly mixed with 1050 parts of polyethylene (density of 0.96 
g/cm.sup.3, melting index of 23 g/10 min., stabilized as in Example 36) in 
a plowshare mixer. 
The preparation of the test samples and their examination are effected as 
has been described in Example 1. 
The properties of the test samples are shown in Table VII. 
TABLE VII 
______________________________________ 
tensile 
elonga- tensile impact impact 
tion strength strength strength 
Example % N/mm.sup.2 
mJ/mm.sup.2 
mJ/mm.sup.2 
______________________________________ 
compa- 20 23 40 80 
rison 
36 30 29 w/o b. 120 
37 44 24 w/o b. 110 
______________________________________ 
EXAMPLE 38 
500 Parts of calcium carbonate having an average particle diameter of 5 
.mu.m and a speficic surface (BET) of 1 m.sup.2 /g and 5 parts of 
dodecane-phosphonic acid are mixed for 20 minutes in a high-speed mixer at 
1200 rpm at 80.degree. C. 
450 Parts of the calcium carbonate thus treated are thoroughly mixed with 
1050 parts of polypropylene (density of 0.905 g/cm.sup.3, melting index of 
7 g/10 min., containing 0.5% by weight of a phenolic stabilizer and 1.75% 
by weight of a sulfur-containing co-stabilizer) in a plowshare mixer. 
For a comparison test, 450 parts of untreated calcium carbonate are mixed 
in the same manner with 1050 parts of polypropylene. 
The further processing of the mixtures, the preparation of the test samples 
and the testing are effected as has been described in Example 1. 
The properties of the test samples are shown in Table VIII. 
TABLE VIII 
______________________________________ 
tensile 
elonga- tensile impact impact 
tion strength strength 
strength 
E-module 
Example 
% N/mm.sup.2 
mJ/mm.sup.2 
mJ/mm.sup.2 
N/mm.sup.2 
______________________________________ 
compa- 200 28 24 230 0.96 
rison 
38 440 32 36 210 1.32 
______________________________________ 
EXAMPLES 39 to 45 
As has been described in Example 15, the same polyethylene is mixed with 
varying amounts of the same calcium carbonate which has been modified with 
1% by weight of octane-phosphonic acid, calculated on the amount by weight 
of filler, and is further processed. For reasons of comparison, mixtures 
with untreated calcium carbonate are prepared each time. 
The properties of the test samples are shown in Table IX. 
TABLE IX 
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tensile 
elonga- tensile 
impact impact 
% of tion strength 
strength 
strength 
Example CaCO.sub.3 
% N/mm.sup.2 
mJ/mm.sup.2 
mJ/mm.sup.2 
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comparison 
10 44 27 w/o b. 130 
39 10 74 27 w/o b. 140 
comparison 
20 44 24 w/o b. 110 
40 20 54 26 w/o b. 120 
comparison 
30 22 23 65 80 
41 30 40 23 w/o b. 110 
comparison 
40 19 21 23 85 
42 40 25 22 w/o b. 100 
comparison 
50 10 20 7 70 
43 50 15 21 66 85 
comparison 
60 7 17 2.8 60 
44 60 10 18 7.0 70 
comparison 
70 6 14 1.8 -- 
45 70 8 15 4.0 -- 
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