U.S. patent application number 10/975369 was filed with the patent office on 2005-05-05 for screw cap composition.
This patent application is currently assigned to Solvay Polyolefins Europe - Belgium (S.A.). Invention is credited to Baudimont, Guy De Cambry De, Berghe, Pascal Vanden.
Application Number | 20050096434 10/975369 |
Document ID | / |
Family ID | 8181273 |
Filed Date | 2005-05-05 |
United States Patent
Application |
20050096434 |
Kind Code |
A1 |
Baudimont, Guy De Cambry De ;
et al. |
May 5, 2005 |
Screw cap composition
Abstract
A screw cap is disclosed comprising a composition based on a
multimodal ethylene polymer having a standard density (SD) greater
than 950 kg/m.sup.3 and a melt flow index MI.sub.2 of less than 10
g/10 min, said multimodal ethylene polymer comprising from 35 to 65
wt %, based on the total weight of the multimodal ethylene polymer,
of a fraction of ethylene polymer (A) having an SD(A) of more than
965 kg/m.sup.3 and a melt flow index MI.sub.2(A) of at least 10
g/10 min, and from 65 to 35 wt % based on the total weight of the
multimodal ethylene polymer, of a fraction of a copolymer (B) of
ethylene and at least one alpha-olefin containing from 3 to 12
carbon atoms, and having a melt flow index MI.sub.2(B) of less than
10 g/10 min and a content of said alpha-olefin(s) of from 0.1 to 5
mol %. This composition is said to demonstrate an excellent balance
between ESCR, injectability and impact resistance, together with
excellent organoleptic properties.
Inventors: |
Baudimont, Guy De Cambry De;
(Brussels, BE) ; Berghe, Pascal Vanden; (Limal,
BE) |
Correspondence
Address: |
FINNEGAN, HENDERSON, FARABOW, GARRETT & DUNNER
LLP
901 NEW YORK AVENUE, NW
WASHINGTON
DC
20001-4413
US
|
Assignee: |
Solvay Polyolefins Europe - Belgium
(S.A.)
|
Family ID: |
8181273 |
Appl. No.: |
10/975369 |
Filed: |
October 29, 2004 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10975369 |
Oct 29, 2004 |
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10494731 |
May 6, 2004 |
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10494731 |
May 6, 2004 |
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PCT/EP02/12382 |
Nov 6, 2002 |
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Current U.S.
Class: |
525/240 |
Current CPC
Class: |
C08L 2205/02 20130101;
C08L 23/0815 20130101; C08L 23/04 20130101; C08L 23/06 20130101;
C08L 23/0815 20130101; C08L 2666/04 20130101; C08L 2666/06
20130101; C08L 2666/04 20130101; C08L 2666/06 20130101; C08L 23/06
20130101; B65D 41/00 20130101; C08L 23/04 20130101; C08L 23/06
20130101; C08L 2205/025 20130101 |
Class at
Publication: |
525/240 |
International
Class: |
C08L 023/00 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 9, 2001 |
EP |
01204466.5 |
Claims
1-15. (canceled)
16. Screw cap comprising a composition based on a multimodal
ethylene polymer having a standard density (SD) greater than 950
kg/m.sup.3 and a melt flow index MI.sub.2 of less than 2 g/10 min,
wherein said multimodal ethylene polymer includes from 35 to 65 wt
%, based on the total weight of the multimodal ethylene polymer, of
a fraction of ethylene polymer (A) having an SD(A) of more than 965
kg/m.sup.3 and a melt flow index MI.sub.2(A) of at least 10 g/10
min, and from 65 to 35 wt %, based on the total weight of the
multimodal ethylene polymer, of a fraction of a copolymer (B) of
ethylene and at least one alpha-olefin containing from 3 to 12
carbon atoms, and having a melt flow index MI.sub.2(B) of at least
0.03 g/10 min but less than 10 g/10 min and a content of said at
least one alpha-olefin of from 0.1 to 5 mol %.
17. Screw cap according to claim 16, wherein the multimodal
ethylene polymer has a melt flow index MI.sub.2 of 0.5 to 1.8 g/10
min.
18. Screw cap according to claim 16 or 17, wherein the multimodal
ethylene polymer has an SD of no more than 960 kg/m.sup.3.
19. Screw cap according to claim 16, wherein MI.sub.2(B) is less
than 0.8 g/10 min.
20. Screw cap according to claim 19, wherein MI.sub.2(B) is less
than 0.5 g/10 min.
21. Screw cap according to claim 16, wherein MI.sub.2(A) is 10-400
g/10 min.
22. Screw cap according to claim 16, wherein SD (A) is at least 969
kg/m.sup.3.
23. Screw cap according to claim 16, wherein said multimodal
ethylene polymer includes from 45 to 55 wt % of ethylene polymer
(A) and from 45 to 55% of copolymer (B).
24. Screw cap according to claim 16, wherein copolymer (B) contains
monomer units derived from ethylene and butene-1.
25. Screw cap according to claim 16, wherein the multimodal
ethylene polymer is obtained by polymerization in at least two
reactors connected in series.
26. Screw cap comprising a composition based on a multimodal
ethylene polymer and having an ESCR(B) greater than 800 hours, a
notched Charpy impact resistance greater than 7 kJ/m.sup.2, and an
injectability greater than 2.8 s, wherein the composition is based
on a multimodal ethylene polymer having a standard density (SD)
greater than 950 kg/m.sup.3 and a melt flow index MI.sub.2 of less
than 2 g/10 min, said multimodal ethylene polymer including from 35
to 65 wt %, based on the total weight of the multimodal ethylene
polymer, of a fraction of ethylene polymer (A) having an SD(A) of
more than 965 kg/m.sup.3 and a melt flow index MI.sub.2(A) of at
least 10 g/10 min, and from 65 to 35 wt %, based on the total
weight of the multimodal ethylene polymer, of a fraction of a
copolymer (B) of ethylene and at least one alpha-olefin containing
from 3 to 12 carbon atoms, and having a melt flow index MI.sub.2(B)
of at least 0.03 g/10 min but less than 10 g/10 min and a content
of said at least one alpha-olefin of from 0.1 to 5 mol %.
27. Screw cap according to claim 26, wherein the composition has a
standard density greater than 950 kg/m.sup.3.
28. Screw cap according to claim 26 or 27, wherein the composition
has a melt flow index MI.sub.2 of less than 10 g/10 min.
29. Screw cap according to claim 18, wherein the SD is 951-958
kg/m.sup.3.
Description
[0001] The present invention relates to screw caps comprising a
composition based on multimodal ethylene polymer. It also relates
to a process for manufacturing said caps and their use for the
closure of bottles, in particular bottles containing foodstuffs,
and more particularly fizzy drinks.
[0002] It is known to use polyethylene, and more particularly
bimodal polyethylene, for the manufacture of caps. Thus patent
applications U.S. Pat. No. 5,981,664 and WO 00/71615 describe caps
obtained by injection of a composition comprising two polyethylenes
having different molecular weight distributions. However, the
compositions described in said documents do not have the optimum
properties for the manufacture of caps, more particularly for caps
intended for the closure of bottles containing fizzy drinks.
[0003] We have now found screw caps comprising a composition based
on multimodal ethylene polymer which do not possess the
above-mentioned drawbacks.
[0004] To this end, the present invention relates to screw caps
comprising a composition based on a multimodal ethylene polymer
having a standard density (SD) greater than 950 kg/m.sup.3 and a
melt flow index MI.sub.2 of less than 10 g/10 min, said multimodal
ethylene polymer comprising--
[0005] from 35 to 65 wt %, based on the total weight of the
multimodal ethylene polymer, of a fraction of ethylene polymer (A)
having an SD(A) of more than 965 kg/m.sup.3 and a melt flow index
MI.sub.2(A) of at least 10 g/10 min, and
[0006] from 65 to 35 wt %, based on the total weight of the
multimodal ethylene polymer, of a fraction of a copolymer (B) of
ethylene and at least one alpha-olefin containing from 3 to 12
carbon atoms, and having a melt flow index MI.sub.2(B) of less than
10 g/10 min and a content of said alpha-olefin(s) of from 0.1 to 5
mol %.
[0007] Within the scope of the present invention, the term "screw
caps" is meant screw caps possessing a threaded closure. In most
cases, said screw caps are provided with a tear strip.
[0008] By "multimodal ethylene polymer" is meant an ethylene
polymer comprising at least two fractions having different melt
flow indices (MI.sub.2) so that it possesses a broad or multimodal
molecular weight distribution.
[0009] The multimodal ethylene polymer used in the present
invention has generally a standard density (SD) which does not
exceed 965 kg/m.sup.3. Within the scope of the present invention,
the SD is measured according to the standard ISO 1183-3 (1999). The
SD preferably does not exceed 960 kg/m.sup.3, more particularly not
958 kg/m.sup.3. The SD is preferably at least 951 kg/m.sup.3.
[0010] The multimodal ethylene polymer used in the present
invention preferably possesses a melt flow index (MI.sub.2)
measured at 190.degree. C. under a load of 2.16 kg according to the
standard ASTM D 1238 (1998) of less than 4 g/10 min. MI.sub.2
values of less than 2 g/10 min are particularly preferred. The melt
flow index MI.sub.2 is, in general, at least 0.5 g/10 min, and may
be at least 0.8 g/10 min; values of at least 1.2 g/10 min being
particularly recommended. Melt flow indices of 1.4 to 1.8 g/10 min
are very particularly preferred.
[0011] The fraction of ethylene polymer (A) in the multimodal
ethylene polymer is preferably at least 40%, more particularly at
least 45% by weight compared with the total weight of the
multimodal ethylene polymer. The fraction of ethylene polymer (A)
preferably does not exceed 60 wt %, more particularly it does not
exceed 55 wt % compared with the total weight of the multimodal
ethylene polymer. Good results were obtained with a fraction of
ethylene polymer (A) of 48 to 52 wt % compared with the total
weight of the multimodal ethylene polymer.
[0012] The fraction of ethylene copolymer (B) in the multimodal
ethylene polymer is preferably at least 40%, more particularly at
least 45 wt % by weight compared with the total weight of the
multimodal ethylene polymer. The fraction of ethylene copolymer (B)
preferably does not exceed 60 wt %, more particulary not 55 wt %
compared with the total weight of the multimodal ethylene polymer.
Fractions of ethylene copolymer (B) of 48 to 52 wt % compared with
the total weight of the multimodal ethylene polymer have given good
results.
[0013] The composition used in the present invention generally
contains at least 95%, preferably at least 98% by weight of the
whole of the polymer (A) and the copolymer (B). Most particularly
preferred is a composition consisting mainly of the polymer (A) and
the copolymer (B).
[0014] Preferably, the polymer (A) is an ethylene homopolymer. For
the purposes of the present invention, there is taken to mean by
ethylene homopolymer (A) an ethylene polymer consisting mainly of
monomer units of ethylene and substantially devoid of monomer units
derived from other olefins.
[0015] By ethylene copolymer with one or more alpha-olefins
containing from 3 to 12 atoms of carbons (copolymer (B)) is taken
to mean a copolymer comprising monomer units derived from ethylene
and monomer units derived from at least one alpha-olefin containing
from 3 to 12 atoms of carbon. The alpha-olefin may be selected from
among olefinically unsaturated monomers such as butene-1,
pentene-1, hexene-1, octene-1. butene-1 is particularly preferred.
The content of alpha-olefin in the copolymer (B) is with advantage
at least equal to 0.2 molar %, in particular at least equal to 0.3
molar %. The content of alpha-olefin in the copolymer (B) is
preferably at most equal to 4 molar %, more precisely at most equal
to 3 molar %. Particularly good results are obtained with
alpha-olefin contents in the copolymer (B) of 0.5 to 2 molar %.
[0016] The SD of the polymer (A) (SD(A)) is preferably at least 968
kg/m.sup.3, more particularly at least 970 kg/m.sup.3. With
advantage, the polymer (A) is characterised by a value of
MI.sub.2(A) of at least 30 g/10 min, more particularly at least 50
g/10 min. Preferably, the value of MI.sub.2(A) does not exceed 500
g/10 min, values of less than 400 g/10 min being particularly
preferred. Melt flow indices MI.sub.2(A) of at least 80 g/10 min,
particularly 80 to 200 g/10 min, have given good results.
[0017] Preferably, copolymer (B) is characterised by a value of
MI.sub.2(B) of at least 0.03 g/10 min, more particularly of at
least 0.06 g/10 min. There is preferred most particularly a value
of MI.sub.2(B) of at least 0.08 g/10 min. Preferably, the value of
MI.sub.2(B) does not exceed 2 g/10 min, values of at most 1 g/10
min being particularly preferred. There is preferred most
particularly an MI.sub.2(B) value of at most 0.8 g/10 min, more
preferably no more than 0.5 g/10 min. Melt flow indices MI.sub.2(B)
of 0.08 to 0.8 g/10 min have given good results.
[0018] The multimodal ethylene polymer used in the present
invention may be obtained by any suitable technique. It is
possible, for example, to perform the mixing of the polymer (A) and
the copolymer (B) by any known process such as, for example, the
molten mixing of the two preformed polymers. Preferred, however,
are processes in the course of which the polymer (A) and the
copolymer (B) are prepared in at least two successive
polymerisation stages. In general, first of all the preparation of
the polymer (A) is performed and then the preparation of the
copolymer (B) in the presence of the polymer (A) obtained from the
first polymerisation stage. The polymerisation stages may each be
carried out, independently of one another, in suspension in an
inert hydrocarbon diluent or in gaseous phase. A process comprising
at least two polymerisation stages in suspension in a hydrocarbon
diluent is preferred. The hydrocarbon diluent is generally chosen
from among aliphatic hydrocarbons containing from 3 to 10 carbon
atoms. Preferably, the diluent is chosen from among propane,
isobutane, hexane or their mixtures.
[0019] In addition to the multimodal ethylene polymer, the
composition used in the present invention may contain conventional
additives such as antioxidants, antacids, UV stabilisers, dyes,
fillers, antistatic agents and lubricating agents. The total
content of additives generally does not exceed 5 wt % compared with
the total weight of the composition used in the present invention.
Preferably it does not exceed 2 wt %.
[0020] The composition used for the manufacture of caps according
to the invention may be obtained by any suitable known means. It is
possible, for example, to employ two successive stages, the first
comprising mixing the multimodal ethylene polymer and where
applicable the additives at ambient temperature, the second stage
comprising continuing the mixing in the molten state in an
extruder. The temperature of the second stage is generally from 100
to 300.degree. C., in particular from 120 to 250.degree. C., more
particularly from about 130 to 210.degree. C. An alternative method
comprises introducing the additives and where applicable the other
compounds into the already molten multimodal ethylene polymer.
[0021] It is also possible to prepare, in an initial stage, a
master batch comprising a first fraction of the multimodal ethylene
polymer plus any additives, said master batch being rich in
additives and optionally in other compounds. The master batch is
then mixed with the remaining fraction of the multimodal ethylene
polymer, for example during the manufacture of granules of the
composition.
[0022] The screw caps according to the invention may be obtained by
any known technique for the manufacture of objects. Injection
moulding is particularly well suited.
[0023] The screw caps according to the present invention have good
organoleptic properties which render them suitable to be used on
bottles containing foodstuffs. In addition, they possess a good
resistance to slow cracking. The screw caps according to the
present invention have an acceptable opening torque. They possess
in addition good dimensional tolerances. They are therefore
particularly well suited to being used on bottles containing fizzy
drinks. The invention consequently also relates to the use of the
caps according to the invention for the closure of bottles
containing foodstuffs, more particularly for the closure of bottles
containing fizzy drinks. A further aspect of the invention relates
to screw caps comprising a composition based on a multimodal
ethylene polymer and having an ESCR(B) greater than 800 hours, a
notched Charpy impact resistance greater than 7 kJ/m.sup.2, and an
injectability greater than 2.8 s. Preferably the screw caps of this
aspect of the invention comprise composition is having a standard
density greater than 950 kg/m.sup.3, and/or a melt flow index
MI.sub.2 of less than 10 g/10 min. It is also preferred that they
are based on compositions according to the first aspect of the
present invention.
[0024] The Examples which are described below serve to illustrate
the invention. The meanings of the symbols used in these examples,
the methods of measurement and the units of these quantities are
explained below:
[0025] [A]: fraction of ethylene polymer (A) expressed in wt %
compared with the total weight of the multimodal ethylene
polymer.
[0026] [B]: fraction of ethylene copolymer (B) expressed in wt %
compared with the total weight of the multimodal ethylene
polymer.
[0027] MI.sub.2: melt flow index of the multimodal ethylene
polymer, expressed in g/10 min, measured at 190.degree. C. under a
load of 2.16 kg according to the standard ASTM D 1238 (1998).
[0028] MI.sub.2(A): melt flow index of the ethylene polymer (A),
expressed in g/10 min, measured at 190.degree. C. under a load of
2.16 kg according to the standard ASTM D 1238 (1998); in cases
where the multimodal ethylene polymer is manufactured by a process
of two successive polymerisation stages, said value is measured on
a sample of the polymer (A) taken from the first reactor.
[0029] MI.sub.2(B): melt flow index of the ethylene copolymer (B),
expressed in g/10 min, measured at 190.degree. C. under a load of
2.16 kg according to the standard ASTM D 1238 (1998); in cases
where the multimodal ethylene polymer is manufactured by a process
of two successive polymerisation stages, this value is calculated
on the basis of the MI.sub.2 and MI.sub.2(A) values.
[0030] MI.sub.5(B): melt flow index of the ethylene copolymer (B),
expressed in g/10 min, measured at 190.degree. C. under a load of 5
kg according to the standard ASTM D 1238 (1998).
[0031] SD: standard density of the multimodal ethylene polymer,
expressed in kg/m.sup.3, measured according to the standard ISO
1183-3 (1999).
[0032] SD(A): standard density of the ethylene polymer (A),
expressed in kg/m.sup.3, measured according to the standard ISO
1183-3 (1999); in cases where the multimodal ethylene polymer is
manufactured by a process of two successive polymerisation stages,
this value is measured on a sample of the polymer (A) taken from
the first reactor.
[0033] C.sub.4(B): content of butene-1 of the ethylene copolymer
(B), expressed in molar %. Said content is calculated according to
the following equation: 1 C 4 ( B ) 100 .times. C 4 total [ B ]
[0034] in which
[0035] C.sub.4 total represents the content of butene-1 of the
multimodal ethylene polymer used, determined by nuclear magnetic
resonance in .sup.13C, and is expressed in molar %.
[0036] ESCR: resistance to slow cracking, measured by the following
method: 10 caps are screwed onto stainless steel preforms, the
assembly is then immersed in a water bath at 60.degree. C. A
hydrostatic pressure of 8 bar is applied in the preform. The
service life, expressed in hours, is recorded as soon as a break
appears.
[0037] ESCR-A: resistance to slow cracking, expressed in hours,
measured according to the standard ASTM D 1693 (1980), condition A,
by immersion in an aqueous solution containing 10 vol % of
nonylphenoxy-poly(ethyleneo- xy)ethanol at 50.degree. C. of a plate
obtained by compression of the composition used in the present
invention according to the standard ASTM D 1928 (1980).
[0038] ESCR-B: resistance to slow cracking, expressed in hours,
measured according to the standard Bell Telefon Test ASTM D 1693
condition B, with temperature=23.degree. C. and 25% of
nonyl-phenol-ethoxyl. Compression moulding of samples according to
ASTM D1928.
[0039] OT: opening torque, measured by the following method: Ten
caps are screwed onto 33 cl glass bottles by means of a Zalkin
single-head laboratory machine and so as to close the caps with a
screwing torque fixed at 2.83 Nm. The unscrewing torque is
measured. The OT value is the mean of the values obtained for the
ten caps and is expressed in Nm.
[0040] OI: organolepticity index, measured by the following method:
33 g of the composition based on ethylene polymer in granule form
are suspended in 1 litre of water for 4 hours at 60.degree. C.
Then, 6 different operators taste the water of the suspension,
which is cooled to ambient temperature, and evaluate its taste.
They each give a mark from 1 to 4 by comparison with a water sample
that has undergone the same treatment in the absence of granules,
the mark of 1 corresponding to the taste of said water sample. A
high mark corresponds to a bad taste. The organolepticity index
(OI) is the mean of the marks of the 6 operators.
[0041] OIS: organolepticity index after exposure to the sun,
measured by the following method: 33 cl glass bottles are filled
with water and fitted with caps injected-moulded 1 week before.
Said bottles are exposed for 48 hours at 40.degree. C. at 600
W/m.sup.2 to the solar spectrum in a sun test apparatus. Then, the
taste of the water is tested by the same method as that described
above for the determination of the OI.
[0042] Taste: 25 g of polymer pellets in 500 ml of mineral water
are maintained at 60.degree. C. for 48 hours, before cooling to
23.degree. C. for 24 hours. The solution is then filtered and four
50% dilutions carried out to give five solutions, ranging from
Solution 1, the <<mother solution>> to Solution 5, a
1/16 dilution. Each solution is tasted by the assessor, starting
with the most dilute solution and finishing with the mother
solution. When any taste is detected, the sample is accorded a
score corresponding to the number of that solution (5, 4, 3, 2, 1).
Consequently the higher the score, the worse the taste. If no taste
is detected even in the mother solution, the score is 0. The final
Taste value is the average of all scores (panel of 6 assessors at
least).
[0043] Odour: 400 ml of polymer pellets are placed in a 500 ml
glass flask, which is sealed and heated to 80.degree. C. for 30
minutes. The flask is then allowed to cool to 23.degree. C.
Evaluations are compared with a standard resin, which is taken to
have a constant odour level of 0.5. The cooled pellets are smelt by
each assessor in comparison with the standard. Scores can be given
from 0 (no odour relative to standard) to 3 (strong odour) in
increments of 0.5. The final Odour value is the average of all
scores (panel of 6 assessors at least).
[0044] Notched Charpy Impact Resistance: this was measured
according to ISO 179.
[0045] Injectability: This is 1/viscosity at 1000 s.sup.-1 and
190.degree. C., with a 15/1 die.
[0046] .O slashed..sub.m, .O slashed..sub.min, .O slashed..sub.max:
respectively mean, minimum and maximum diameter, calculated on ten
measurements for caps having a nominal diameter of 30.5 mm.
[0047] .sigma..sub.m, .sigma..sub.min, .sigma..sub.max:
respectively mean, minimum and maximum distortion of the plate of
the cap, calculated on ten measurements.
EXAMPLES 1, 2
[0048] In an extruder, there was mixed (at 190.degree. C.) and
granulated a composition consisting of:
[0049] 99.7 parts by weight of multimodal ethylene polymer
manufactured by a process such as that disclosed in the patent
application EP 603935A;
[0050] 0.2 part by weight of calcium stearate;
[0051] 0.1 part by weight of
[tris(2,4-di-t-butyl-phenyl)phosphite].
[0052] The characteristics of the ethylene polymers used in the
examples are given in Table 1 below.
[0053] Screw caps were manufactured by injection moulding on a
Netstal machine fitted with an 18-cavity mould.
[0054] The characteristics of the caps obtained are also contained
in Table 1 below.
EXAMPLES 3R-5R (COMPARATIVE)
[0055] The operations of Examples 1 and 2 were repeated, but using
ethylene polymers not conforming to the invention and whose
characteristics are given in Table 1 below.
[0056] A comparison of Examples 1 and 2 with Example 3R shows that
the screw caps according to the invention have a far superior
resistance to cracking than a cap not conforming to the
invention.
[0057] A comparison of Examples 1 and 2 with Examples 5R and 4R
respectively shows that the screw caps according to the invention
have a far better resistance to slow cracking.
EXAMPLES 6R, 7R (COMPARATIVE)
[0058] In Examples 6R and 7R, ethylene polymers of the monomodal
type were used.
[0059] A comparison of Examples 1 and 2 with Examples 7R and 6R
respectively shows that the screw caps according to the invention
possess a resistance to slow cracking which is superior to that of
caps based on a monomodal ethylene polymer. A comparison of Example
1 with Example 7R shows in addition that the screw caps according
to the invention have organoleptic properties (OI and OIS) and
dimensional tolerances at least as good, if not better, than those
obtained from a composition based on a monomodal polyethylene, with
equivalent opening torque values.
EXAMPLES 8-12
[0060] For these Examples of the invention, the two blocks were
made separately and then flake blended. Their properties are shown
in Table 2, together with those of Example 1 and also Examples 13R
and 14R.
EXAMPLES 13R, 14R
[0061] These are commercial products used for the manufacture of
caps. Example 13R is monomodal, Example 14R is bimodal.
1TABLE 1 Property Unit 1 2 3R 4R 5R 6R 7R MI.sub.2 g/10 min 1.6 1.5
1.6 10.1 10.1 2 1.7 SD kg/m.sup.3 951.6 955.5 964.9 955.7 952.7 957
952.1 MI.sub.2(A) g/10 min 117 121 131 137 122 -- -- SD(A)
kg/m.sup.3 970.6 970.7 970.9 971 970.7 -- -- MI.sub.2 (B) g/10 min
0.29 0.27 0.2 2.39 2.74 -- -- [A] wt % 49.3 49.6 50 49.5 50.1 -- --
[B] wt % 50.7 50.4 50 (*) 50.5 49.9 -- -- C4(B) mol % 1.2 0.8 0 (*)
1.1 1.6 -- -- ESCR hour 214 54 3 4 -- 18 58 ESCR-A hour >500 217
16.7 0 4.4 12 43 OT Nm 2.54 2.20 1.98 -- -- 2.15 2.37 OI -- 1.4 1.7
-- -- 1.8 -- 1.8 OIS -- 2.7 2.5 -- -- -- -- 3.2 .O slashed..sub.m
mm 30.5 30.6 -- -- -- -- 30.6 .O slashed..sub.min mm 30.4 30.45 --
-- -- -- 30.35 .O slashed..sub.max mm 30.6 30.7 -- -- -- -- 30.8
.sigma..sub.m mm 0.4 0.4 -- -- -- -- 0.5 .sigma..sub.min mm 0.18
0.15 -- -- -- -- 0.3 .sigma..sub.max mm 0.68 0.69 -- -- -- -- 0.76
(*) ethylene homopolymer
[0062]
2TABLE 2 Property Unit 1 8 9 10 11 12 13R 14R MI.sub.2 g/10 min
1.60 1.68 0.60 0.86 0.69 0.53 2.1 3.7 SD kg/m.sup.3 951.6 952.4
952.7 952.9 952.8 951.2 950.9 953.6 MI.sub.2 (A) g/10 min 117 110
151 125 245 391 -- -- SD(A) kg/m.sup.3 970.6 971.4 971.2 971.7
972.5 972.4 -- -- MI.sub.2 (B) g/10 min 0.29 0.23 0.12 0.06 0.12
0.06 -- -- MI.sub.5 (B) g/10 min 0.7 0.35 0.18 0.36 0.19 -- -- [A]
% weight 49.3 50.0 45.0 55.0 45.0 50.0 -- -- [B] % weight 50.7 50.0
55.0 45.0 55.0 50.0 -- -- SCB comp. nb/1000 C 3.6 2.9 2.2 2.7 2.1
2.7 -- -- C4(B) calc. % molar 1.44% 1.17% 0.81% 1.21% 0.77% 1.09%
-- -- Notched kJ/m.sup.2 7.3 7.4 10.4 8.2 9.8 9.8 13.0 5.1 Charpy
23.degree. C. ESCR-B hour >1000 >1000 >1000 >1000
>1000 >1000 600 300 Injectability s 3.85 3.45 2.86 3.57 2.94
3.33 2.56 4.55 OI -- 1.4 -- -- -- -- -- 1.3 -- Taste -- 0.2 0 0.2
0.8 0 1.4 0.2 0 Odour -- 0.1 0 0.2 0.7 0.1 0.4 0.1 0.5
[0063] The results in the above Tables emphasize the excellent
balance between ESCR, Injectability and Impact Resistance, together
with the excellent organoleptic properties of the compositions of
the invention in comparison with the prior art and also commercial
resins.
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