PRODUIT THERMOPLASTIQUE COMPRENANT UN POLYMERE DE CHLORURE DE VINYLE ET UN POLYETHYLENE CHLORE

THERMOPLASTIC COMPOSITION CONSISTING OF A VINYL CHLORIDE POLYMER AND A CHLORINATED LOW PRESSURE POLYETHYLENE

Abrégé anglais

Thermoplastic composition
Abstract of the disclosure
Thermoplastic compositions essentially consisting of
vinyl chloride copolymers and chlorinated low pressure poly-
ethylene having a reduced specific viscosity of from 1 to 5
dl/g,a residue value of from 2 to 40% and a swelling value of
from 10 to 70%,which chlorinated polyethylene is prepared in
chlorhydric acid, optionally in the presence of silicic acid
and siloxane oil.
The compositions according to the invention are well suit-
able for the dry-blend technique. They may be used for
making pipel, profiles, plates, sheets, cables, flexible
tubes, injection moulded particles and other shapes
and structures.

Revendications

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A thermoplastic composition consisting essentially of
a) 98 to 50% by weight of a vinyl chloride polymer and
b) 2 to 50% by weight of a chlorinated low pressure poly-
ethylene having a chlorine content of 25 to 42% by
weight, a reduced specific viscosity of 1 to 5 dl/g,
a residue value of 2 to 40%, measured by extraction in
a 1 : 1 mixture of toluene and acetone, and a swelling
value of 10 to 70 %, measured in methylcyclohexane,
the chlorinated polyethylene being prepared by chlorination
of low pressure polyethylene in aqueous hydrochloric acid
of 10 to 35 % strength by weight in the presence of 0 to
2 % by weight of silicic acid and 0 to 1.0 % by weight
of siloxane oil, the percentages being calculated on
the polyethylene, consisting of the recurring unit
<IMG>
wherein R1 and R2 each represent an alkyl radical, an
aryl radical, a phenyl or an aralkyl radical and x is
an integer of from 10 to 1,000, at a chlorination
temperature of from 50 to 130°C, at least 10 % by weight
of the chlorine being incorporated at a temperature of
from 120 to 130°C.
2. A thermoplastic composition as claimed in claim 1, in
which the chlorinated polyethylene was prepared by chlorination
11

starting at 50 to 100°C and ending at 120 to 130°C.
3. A thermoplastic composition as claimed in claim 1, in
which the chlorinated polyethylene was prepared by chlorination
starting at 70 to 90°C and ending at 120 to 130°C.
4. A thermoplastic composition as claimed in claim 1,
claim 2 or claim 3, in which the chlorinated polyethylene has
a chlorine content of from 30 to 40%.
5. A thermoplastic composition as claimed in claim 1
claim 2 or claim 3, in which the chlorinated polyethylene was
prepared from low pressure polyethylene which has been thermally
treated or presintered at a temperature in the range of from
100°C to its crystallite melting point.
6. A thermoplastic composition as claimed in claim 1,
claim 2 or claim 3 in which the vinyl chloride polymer is poly-
vinyl chloride.
7. A thermoplastic composition as claimed in claim 1,
claim 2 or claim 3 in which the vinyl chloride polymer is a co-
polymer of vinyl chloride with 0.01 to 20% by weight of another
monomer selected from the group of vinyl acetate, acrylic acid
esters and methacrylic acid esters.
8. A thermoplastic composition as claimed in claim 1,
claim 2 or claim 3, in which the vinyl chloride polymer is a co-
polymer of vinyl chloride with 1 to 5 % of a monomer selected
from the group of vinyl acetate, acrylic acid esters and meth-
acrylic acid esters.
12

9. A thermoplastic composition as claimed in claim 1,
claim 2 or claim 3, in which the viscosity number of siloxane
oil is in the range from 1000 to 500,000 centistokes.
10. A thermoplastic composition as claimed in claim 1,
claim 2 or claim 3 in which the quantity of silicic acid is
from 0.1 to 1 % by weight.
11. A thermoplastic composition as claimed in claim 1,
claim 2 or claim 3, in which the silicic acid has an average
particle size of from 1 to 50 µm and an inner surface of
from 50 to 4002cm /g (according to BET).
12. A process for the preparation of a thermoplastic
composition in which
a) 98 to 50 % by weight of a vinyl chloride polymer is
mixed with
b) 2 to 50 % by weight of chlorinated low pressure poly-
ethylene having a chlorine wherein the polyethylene
has a chlorine content of 25 to 42 % by weight, a
reduced specific viscosity of 1 to 5 dl/g, a residue
value of 2 to 40 %, measured by extraction in a 1 : 1
mixture of toluene and acetone, and a swelling value
of 10 to 70 %, measured in methylcyclohexane, and is
prepared by chlorination in hydrochloric acid of 10 to
30 % strength by weight in the presence of 0 to 2 %
by weight of silicic acid and 0 to 1.0 % by weight
of siloxane oil, consisting of the recurring unit
13

<IMG>
wherein R1 and R2 each represent an alkyl radical,
an aryl radical, a phenyl or an aralkyl radical and
x is an integer of from 10 to 1,000, the percentages
being calculated on the polyethylene, at a chlori-
nation temperature of from 50 to 130°C, at least 10 %
by weight of the chlorine being incorporated at a
temperature of from 120 to 130°C.
13. A process for the preparation of a thermoplastic
composition as claimed in claim 12 in which the viscosity
number of the siloxane oil is in the range of from 1000 to
500,000 centistokes.
14. A process for the preparation of a thermoplastic
composition as claimed in claim 12 in which the quantity of
silicic acid is from 0.1 to 1 % by weight.
15. A process for the preparation of a thermoplastic
composition as claimed in claim 12, claim 13 or claim 14 in
which the silicic acid has an average particle size of from 1
to 50 µm and a inner surface of from 50 to 400 cm2/g (according
to BET).
14

Description

HOE 73iF 264
l~S~580 g
Thi~ invention relatQq to a th~rmopla~tic compositlon con-
sisting of a vinyl chloride polymer and ~ chlorinated low pres-
sure polyethylene.
It has been proposed to elastify polyvinyl chloride and
vinyl chloride copolymers by the addition of chlorination pro-
ductY of polyolefins obtained by chlorinating polyolefins in
aqueous suspension and having a chlorine content of from 25 to
50 % by weight (cf. German Patent 1,469,990 and German Patents
1,236,774 and 1,266,969).
To obtain chlorination products having a good elastifying .
effect combined with a sufficient fineness o~ grain ~he chlorin-
ation has to be carried out in the presence of fine-grained
inert, inorganic or organic additives to ~void agglomeration.
As inorganic additives silicic acid or kieselguhr have been
proposed (cf. ~erman Patent 1,420,407).
The relatively 1arge amount of silicic acid, whcih must be
added to the ch~ination reaction as anti-agglomeration agent
and which partially remains in the final blend when the chloro-
polyolefln i~ mixed with polyvinyl chloride, haq a detrimental
ef~ect on the rheological and mechanical p~operties of the
blend.
It has now been ~ound that mixtures o~ ~rinyl chloride poly-
mers and chlorination products o~ polyole~ins can be produced
which d~hot have the a~oresaid disadvanta~es and are well
suitable for dry blend ~echnique by using ~ chlorinated low
pressure polyethylene prepared by chlorina~ing in aqueous hyd*o- ~ :
chloric acid, pre~erably in the presence ~ silicic acid having
a large sur~ace ~nd a si'oxane oil.
2g The present in~ention provides a thermoplastic composition
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. HOE 73/F 264
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essentially consisting of
a) 98 to 50 % b~ weight of a vinyl chloride polymer and
b) 2 to 50 ~ by weight of a chlorinated low pressure poly-
ethylane. havlng a chlorine content of 25 to 42 % by weight,
a reduced specific viscosity o~ 1 to 5 dl/g, a residue
value of 2 to 40 %, measured by extraction with toluene~ i
acetone in a proportion of 1 : 19 and a swelling value of ,;
10 to 70 ~, measured in methylcyclohexane, and obtained by
chlorinating a low prcssure polyethylene in aqueous hydro-
chloric acid having a strength of from 10 to 35 ~, preferably
15 to 30 ~ in the presence of O to 2 ~ by w0ight of silicic
acid and O to 1.0 % by weight of a siloxane oil, the percentages ~.
being calculated on the low pressure pol~-e~ylene used, at a
chlorination temperature of from 50 to 130C, at least 10 % by
welght of chlorine being incorporated at a tamperature of from
120 to 130C.
,:
The present invention also provides a process for the
manufacture of a thermoplastic composition by mi~ing .
a) 98 to 50 ~ by weight of a vinyl chloride polymer and
b) 2 to 50 ~ by we~ght of a chlorinated low pressurs poly-
, ethylene
ha~ing a chlorine content of from 25 to 42 % by weight, a re-
duced speci~ic viqco~ity of 1 to 5 dl~g, a residue value of from
2 to 40 %, measured by extraction with toluene/acetone in a
proportion of 1 : 1, and a swelling valu~ of ~rom 10 to 70 %,
measured in methylcyclohexane, prepared by chlorinating a pre-
~erably fine-grained low pressure polyeth~lene in aqueous hydro-
chloric acid of`10 to 35 ~, preferabl~ 15 to 30 ~, ~trength in
Z~ the presence of O to ~ % by weight of silioic acid and O to 1.0~ -
~, _ 3 _
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~OE 73/F 264
~(~5~5~ilV ~ '
by weight of a i~iloxane oil, the p~rcentag0s being calculated
on the starting polyethylene~ at a chlorinatlon temperature o~
from 50 *o 130C, the low presiqure polyethylene being possibly
thermally treated or prssintered at a temperature in the range
o~ from 100C~-i~ cryAtallite melting point and at least 10 %
of the chlorine being incorporated at a temperature of from 120
to 130C~
The thermoplastic composition consists of 98 to j50 % by
weight pre~erably 95to 80 % by weigh*,of polyvinyl chloride or
a copolymer o~ vinyl chloride with other comonomers, such as
vinyl acetate acrylic acid esters or methacrylic acid esters,
the amount o~ comonomer units in the polymer being at most 20
by weight, preferably 1 to 5 % by weight. The K value o~ the
polymer is expediently in a ranga o~ from 50 to 80.
The remainlng ~ to 50 % by weight, pr~ferably 2 to 20 ~ by ~`
weight o~ the thermoplastic composition of the invention consists
of a chlorinated low pressure polyethylene o~ high molecular
weight containing 25 to 42 % by weight, p~ferably 30 to 40 $
by weight,o~ chlorine. The distribution o~ the chlorine atomes ~;
2n in the polyethylene grains, i.e. the degr~e of "pen~rating or
through chlorination" iq oharacterizèd by the reisidue value
according to the toluene/acetone method and the swelling value ~ ;
in methylcyclohexan~. The chlorinated low ~resqure polyethylene
suitable for making the compositions of the invention shall have
a residue value of 2 to 40 ~, pre~erably 2 to 30 %, and a swel-
llng value of 10 to 70 %, pre~erably 20 to 50 %. ~oreover, it
shall have a reduced specific viscosity o~ 1 to 5 dl/g, pre-
~erably 1 to ~.5 dljg.
29 The chlorinated low pre~ure polyethylene o~ high molecular
.
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OE 73/F 264
-" ~0515~0.
~eight is fins-grainQd and-can readily b~ mi~ed homogeneously
with the ~inyl chloride polymer powder.
The chlorinated low pressure polyethylene to be used
according to the invention is produced ~y chlorinatin~ ~ne-
grained low pressure polyethylene, ~hich may have been therm-
ally treated or pre-sintered for 5 to 300 minutes at a temper-
ature of from 100 C to its crystallite melting point (cf.German
Offenlegungsschrift 1,720,800), in hydrochloric acid expedi-
`ently 3 to 30 times the amount of acid is used, referred to the
low pressure polyethylene. The chlorination is started at a
temperature of from 50 to 100C and terminated at 120 to 130C.
The chlorination is advantageously started in a temper-
ature range of from 70 to 90C, continued with continual
temperature increase and terminated at ~ t~mperature ranging
from 120 to l30 C, Alternati~ely, the chlorination can be
effected in two steps, i.e, it is started at a temperature of
from 50C to 100 C, the chlorine supply is interrupted while
the temperature is raised to 120 to 130C and the chlorination
i9 then conti~ued and terminated at that temperature.
The low pressure polyethylene used as starting material
ha~ a reduced specific viscosity of 1 to ~ dl/g, preferably 1
to 3.5 dl/g-
By silicic acid present in the chlo~ination as agglomer-
ation inhibitor the ~arious hydrous or anhydroua types of
finely porous silicon dioxide prefarabl~ having a large sur-
face are understood`. Their inner surface should expediently be
in the range of from 50 to 400 CD /g acGording to BET (Brunauer,
Emmet and Teller)~ prefe~abl~ 150 to 300 cm2/g.
29 In goneral the silicic acld ha~ a ~ean partlcle size of
- 5 -
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~ E 73/F 264
1~5:1581~ ' ~
from 1 to 50 ~ . 1. :
By the addition of 9il~ CiC acid an~ ~ilo~ane oil the anti-
ag~lomeration e~ect o~ hydrochloric acid is impro~ed,
Such an addition i~ therefore preferr~d. In gen~ral 0.1 to 2 %,
pre~erably 0.1 to 1 % by weight Or silieic acid in combination
with 0.01 to 1.0, preferably 0.02 to 0.7 % by ~eight,of
.~$10~ane oil, each tima caloulated on th~ low pressure poly-
ethylene used, are su~ficisnt. The a~ount of ~ilicic acid and
~iloxane oil is not strictly limited, in 90me cases higher
amounts may also be used, whereby the agglomeration inhibition
1~ further impro~ed but disa~vantages fo~ the blend with poly-
vinyl chloride must be taken into consideration.
The organo-silicon compounds or sil~ana oils to be used
aocording to the in~ention are liquid pol~iloxanes consicting
f the recurring unit
~~1 - ~ :,
-o-fi_ _ - ~
OR2 x
- in which Rl and R2 each represents an alkyl radical preferably
haYing from ~ to 6 carbon atom~,an aryl rad~c~l,preferably
a phenyl or an aralkyl radical preferably ha~ing from 7 to 12
carbon atom~,and X is an integer of ~ro~ 10 to 1,OOO.The ~i5-
cosity of the siloxane oils at Z~ C issuitably inthe ra~ ~ ~om ro
to 500,000 centistokes, more suitably 500 to 50,000 centi-
Jtokes. There are mentioned, by way of e~a~ple, dimethyl-,
diethyl-, dipropyl-, methyl-ethyl-, dioc~y~-, dihèxyl-, me~hyl-
propyl-, dibutyl- and didodeorl-poly~iloxan.es. ~ompounds o~
.29 the dimethyl-polyYiloxaIl~ series proved to ~e especially ad-
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~~ 73/F 264
51~80 ~ ,
vantageous. -
The 9ilicic acid component and the polysiloxane, which are
pos~ibly pre-mixed, are expediently added prlor to or at the
beginning of the chlorination within a temperature interval in
which the melting point o~ the polyethylene is not yet reached.
According to another mode of operation the ~ilicic acid is
first added alone and the siloxane oi7 is then admixed during
the course of chlorination. A pos~ible ~light agglomeration can
be counter-acted at least partially by the later addition of
siloxane oil, even if it is made prior to drying.
It i9 also possible, o~ course, to add the intended amount
of qiloxane oil in portions during ~ome or all process steps.
Tha thermoplastic composition according to the invention
may additionally contain known PVC ~tabilizers, ~or example
barium or cadmium laurate, epoxide stabiliz~r~, organic phos- ;
phiteq, tin or lead compounds, as well as ~ther known additi~es.
for example W absorbers, lubricants, prnoes9ing auxiliaries,
dyes and pigments.
Depending on the proportion o~ chlor~nated low pressure
polyeth~lene, the thermoplastie compo~itiqn o~ the in~-ention e~n
be used for making pipes, profiles, plate~, sheets, cables,
fle~ible tubes~in~ection moulded articles and other shaped
structures. Owing to the uniform ~ineness o~ the grain,~the
composition can be easily prooessed by the dry blend technique.
Mi~ing of the component9 in the plasticize~ ~tate i9 not required.
To characterize the chlorinated low pressure polyethylenes
to be uqed according to the in~ention the following met~ods
were u~ed:
29 1) Residue Yalue accordlng to the tolue~e~acetone (TAC) method:
~ _ 7 _
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~ HOE 7~ 264
--` lOSle~
4 grams of the chloropolyeth~ylene to be te~ted were re-
fluxed for 1 hour in 100 ml of a 1 : 1 mixture o~
toluene and acetone. The amount of i~soluble re~idue
consisting of insufficiently chlorinated portions is
a measurement for the through chlorination of the poly-
ethylene particles. The smaller the residue the better the
chlorination product is suitable for the compositions of
the invention. I -
2) Swelling value in methylcyclohexane (MCH)-
The increase in weight of a sample after a 24 hour storage
in methylcyclohexane is a ~urther measurement for the
through chlorination of the polyethylene particles.
Portions which have not been chlorinated to a sufficient
extent ~well very little. Products having a high swelling
value are e~pecially ~uitable.
The ~ollowing examples illustrate the invention.
E X A M P L E 1-
.
The chloropolyethylene used was prep~red as follows:
In a chlorination vessel 100 parts by~ weight of low pressure
polyethylene having a reduced specific vi~c09ity of 1.3 dl/~,
in 900 part~ by weight of 20 ~ hydrochloric acid were chlorin-
ated, first at 80C until a chlorine cont~t of 28 ~ by weight
had been reached and then at 121.5C to a ~inal chlorine
' content of 39.2 % by weight.
The product had a TAC value of 13 ~ and a MCH value of
14 %.
A mixture of 10 part~ b~ waight o~ the abo~e chlorination
product and 90 parts b~ weight of suspen~ion pol~vinyl chloride
29 having a K value o~ 70 was rolled for 10 ~inutes at 175C with
- 8 -
'':` . ' ~ '` ` . `' ' ''.~ ', ' ''' ,':' ' ':

EOE 73/~ 264
S~SE~Q
the addition of 3 part~ by weight Or barium/cadmium stabilizer
and 1 part by weight of diphenyl-Octyl ph~phite. The plates
moulded from the blend had the ~oll~wing ~alues
Notched impact strength acoording t~ DIN 53,453 41.7 cm g/cm2
Impact strength at -20C according to D~N 53,453 "without break"
Notched tensile impact strength (DI~ 53,4~8) 197 cmkg/cm
COMPARATIVE EXAMPLE
The same low pressure polyethylene was chlorinated under
the conditions specified above~ but in wa~er without additio~
of hydrochloric acid. The polymer agglomerated to a large
extent 90 that further ch~rination Wa9 much impeded. A chlorin-
ation product was obtained having a chlorine contentlof 39.1 ~ ~`
by weight, a TAC value of 45 ~ and a MC~ valua of 3 ~. A b1end
of 10 % by weight of the said chlorinati~n prod~ct with 90
by weight of suspension polyvinyl chloride having a K value
of 70, prepared under the conditions of Example 1, was found
to have a notched impact strength of 19.2 cmkg~cm and an
impact strength at -20 C "without ~reak", according to
DIN 53,453, and a notched ten~ile impact strength of 102 cmkg/cm~
according to DIN 53,448.
E X A M P L E 2: `
In a chl~ination vessel 100 parts b~ weight of low pressure
polyethylene having a reduced specif~c ~iscosity of 1.2 dl/g in
1200 parts by weight of 24 ~ hydrochloric acid to which o.48
part by weight of silicic acid havi~g a ~e~ particle size of
12 ~m and an inner surfacQ v~ 200 cm2/g (~ET) and o.o48 part
by weight of siloxane oil having a visco~ity of 1,000 centi-
stokes at 25 C had been added, were chlcrinated,first at 80 C
29 to a chlorine content of 20 ~ by weightj then the temperature
9 _
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HOE _73/F 264
S~i8~ '
was rai4ed to 122C and chlorination wa.4 continued until a
chlorine content of 6.6 ~ by weight was reached. The product
had a TAC value of 33 ~ and a MCH value o~ 16 %.
A blend of 10 part3 of the chloropolyethylene obtained
with 90 parts of suspen~qion PVC having a K value of 70, pre-
pared under the conditions specified in E~ample 1, had a
notched impact strength of 38.9 cmkg/cm and an impact strength
at -20 C "without break".
_ X A M P L E 3:
In a chlorination vessel 100 parts by weight of low
pre~sure polyethylene having a reduced specific viocosity of
3.5 dl/g in 1,000 part_ by weight of 20 ~ by weight h-~drochloric
acid were chlorinated first at 70 C to a chlorinQ content of
20 % by weight, then the tempQraturQ was rais~d to 126C and
chlorination was continued to a final chlorine c~ntent of 36.3 %
by weight. ThQ product obtained had a TAC value of 15 ~ and a
MCH value of 21 %.
A blend of tO parts by weight of the chloropolyethylene
with 90 parts by weight of suqpenRlon P~C having a K value of
70, prepared according to claim 1~ had a notched impact strength
of 51.3 cmkg/cm and an impàct strength at -20C "without
break".
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