U.S. patent application number 15/510954 was filed with the patent office on 2017-10-05 for film with moderate crosslinking.
The applicant listed for this patent is BOREALIS AG. Invention is credited to Mattias Bergqvist, Bert Broeders, Francis Costa, Girish Suresh Galgali, Stefan Hellstrom, Jeroen Oderkerk, Tanja Piel, Bernt-Ake Sultan, Bart Verheule.
Application Number | 20170283566 15/510954 |
Document ID | / |
Family ID | 51570339 |
Filed Date | 2017-10-05 |
United States Patent
Application |
20170283566 |
Kind Code |
A1 |
Costa; Francis ; et
al. |
October 5, 2017 |
FILM WITH MODERATE CROSSLINKING
Abstract
A polymer composition with a polymer of ethylene with a
comonomer with silane group(s) containing units and an additive
that is an organic compound with at least one amine moiety that has
a gel content less than 10 wt % after 7 days at ambient conditions
and a gel content of at least 15 wt % gel content after 14 days at
100.degree. C. The film can be used in a laminate.
Inventors: |
Costa; Francis; (Linz,
AT) ; Bergqvist; Mattias; (Goteberg, SE) ;
Hellstrom; Stefan; (Kungalv, SE) ; Broeders;
Bert; (Beringen, BE) ; Galgali; Girish Suresh;
(Linz, AT) ; Piel; Tanja; (Linz, AT) ;
Sultan; Bernt-Ake; (Stenungsund, SE) ; Verheule;
Bart; (Schelle, BE) ; Oderkerk; Jeroen;
(Stenungsund, SE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
BOREALIS AG |
Vienna |
|
AT |
|
|
Family ID: |
51570339 |
Appl. No.: |
15/510954 |
Filed: |
September 15, 2015 |
PCT Filed: |
September 15, 2015 |
PCT NO: |
PCT/EP2015/071072 |
371 Date: |
March 13, 2017 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C08J 5/18 20130101; C08K
5/3432 20130101; C08K 5/524 20130101; B32B 27/18 20130101; C08K
5/005 20130101; C08K 5/3432 20130101; C08K 5/34926 20130101; C08K
5/3435 20130101; B32B 17/064 20130101; C08K 5/524 20130101; C08K
5/3492 20130101; C08K 5/3492 20130101; B32B 17/1055 20130101; C08L
51/06 20130101; C08L 51/06 20130101; C08J 2323/08 20130101; C08K
5/005 20130101; C08K 5/3435 20130101; C08L 51/06 20130101; C08L
51/06 20130101; C08L 51/06 20130101 |
International
Class: |
C08J 5/18 20060101
C08J005/18; B32B 27/18 20060101 B32B027/18; B32B 17/06 20060101
B32B017/06; C08K 5/3492 20060101 C08K005/3492; C08K 5/3435 20060101
C08K005/3435 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 18, 2014 |
EP |
14185403.4 |
Claims
1. A film comprising a polymer composition: a polymer of ethylene
(a) with a comonomer with silane group(s) containing units that are
hydrolysable and at least one additive (b), wherein the additive is
an organic compound which comprises at least one amine moiety
wherein the film has a gel content less than 10 wt % after 7 days
at ambient conditions and a gel content of at least 15 wt % after
14 days at 100.degree. C., when measured as described in "Gel
content (wt %)".
2. A film according to claim 1, wherein the polymer of ethylene (a)
with a comonomer with silane group(s) containing units that are
hydrolysable is in an amount of at least 80 wt % of the polymer
composition.
3. A film according to claim 1, wherein the polymer of ethylene (a)
with a comonomer with silane group(s) containing units that are
hydrolysable has a density of at least 900 kg/m.sup.3 and an
MFR.sub.2 of 0.1 to 50 g/10 min measured with ISO 1330 at
190.degree. C. and a load of 2.16 kg, whereby the density is
determined according to ISO 1183D and ISA1872-2 for sample
preparation.
4. A film according to claim 1, wherein the polymer of ethylene (a)
with a comonomer with silane group(s) containing units that are
hydrolysable is a low density polyethylene.
5. A film according to claim 1, wherein the polymer of ethylene (a)
with a comonomer with silane group(s) containing units that are
hydrolysable is comprising further polar comonomers (c), excluding
comonomers with silane group(s) containing units that are
hydrolysable.
6. A film according to claim 5, wherein the polymer of ethylene (a)
with a comonomer with silane group(s) containing units that are
hydrolysable is further comprising a total amount of polar
comonomers (c), excluding comonomers with silane group(s)
containing units that are hydrolysable is from 10 wt % to 30 wt
%.
7. A film according to claim 6. wherein the polar comonomers (c),
excluding silane group(s) containing units, is selected from VA,
BA, MA, MMA & EA suitably MA & MMA.
8. A film according to claim 1, wherein the total amount of silane
monomer in the polymer of ethylene (a) with a comonomer with silane
group(s) containing units that are hydrolysable is from 0.1 wt % to
15 wt %.
9. A film according to claim 1, wherein the additive (b) comprising
at least one amine moiety is a stabiliser with at least one UV
agent.
10. A film according to claim 1, wherein the polymer composition
comprising an UV stabiliser and an antioxidant is present in an
amount of 0.1 wt % to 5 wt %.
11. A film according to claim 1, wherein the additive (b)
comprising at least one amine moiety.
12. Process for making a laminate comprising: providing a polymer
composition as in claim 1, extruding the polymer composition to
form a film that has gel content less than 10 wt % after 7 days at
ambient conditions, when measured as described in "Test methods",
and laminating the film without any peroxide decomposition.
13. Process according to claim 12 wherein the additive (b)
comprising at least one amine moiety is added to the polyethylene
composition during film extrusion.
14. A laminate with a front glass layer with at least one layer
that is made of a polyethylene composition comprising: (a) a
polyethylene bearing hydrolysable silane group(s) and (b) at least
one additive, wherein the additive is an organic compound which
comprises at least one amine moiety and wherein the polymer
composition has creep less than <10 mm at 100.degree. C., 24 h,
with a precondition of the creep sample of 7 days 70.degree. C.,
RH95%, when measured as described in "Test methods".
15. A laminate according to claim 14, wherein the layer made of the
polyethylene composition is free from peroxides and tin.
Description
FIELD OF INVENTION
[0001] This invention relates to a film. The film is made from a
polymer composition having a polymer of ethylene (a) with a
comonomer with silane group(s) containing units that are
hydrolysable and an additive (b), wherein the additive is an
organic compound which comprises at least one amine moiety. The
film has the characteristic that it has a gel content less than 10
wt % after 7 days at ambient conditions and a gel content of at
least 15 wt % gel content after 14 days at 100.degree. C.
[0002] The invention also relates to a process for making the film
and a laminate with the film.
BACKGROUND OF INVENTION
[0003] There are many and various laminates. The laminate sought by
this invention is a laminate that comprise at least one glass layer
and at least one layer made of a polymer. The object of these two
layers is good optical properties and good high temperature
properties, i.e. that the laminate can be used in warm places.
Commonly other layers with further functionality are added.
[0004] The most common prior art polymer composition is peroxide
crosslinked ethylene-vinyl acetate (EVA) copolymer which is
extruded as a sheet from an EVA copolymer composition comprising an
organic peroxide as a crosslinking agent and stabilisers.
Crosslinking of the EVA is necessary to provide the layer with
sufficient strength at higher temperatures, because in use, the
temperature is typically 40.degree. C. to 80.degree. C.
[0005] The laminated film is typically produced in a vacuum
lamination process. In this process, the components of the
laminate, after having been assembled, are put into a vacuum
lamination apparatus, in which by application of an increased
temperature of about 100.degree. C. to 180.degree. C., typically
150.degree. C., and an increased membrane pressure for a time of
from about 10 to 30 minutes the laminate is formed under
vacuum.
[0006] One drawback of peroxide crosslinked EVA as layer in a
laminate is the comparatively high temperatures and long lamination
times which are caused by the need to decompose the organic
peroxide in the laminate and in order to achieve the crosslinking
reaction. Thus, the production speed of the laminate is low.
[0007] The use of peroxide crosslinked EVA as polymer layer has,
however, further drawbacks. It is well known that laminates show
optical degradation with time which may occur as a discolouration
of the originally colourless, transparent films. Furthermore, other
problems have been reported such as a delamination at interfaces,
penetration of water and arcing, cracking due to
expansion/contraction stresses, and weathering.
[0008] It is an object of the present invention to provide a film
material with which the drawbacks of the known technologies,
especially the use of peroxide crosslinked polymers as film
material, are greatly reduced. In particular, it is an object of
the invention to provide a film for a laminate which allows to
improve and facilitate the production process of the laminate, e.g.
by shortening the time necessary for lamination of the laminate,
and, at the same time, has a lower tendency to degrade.
[0009] Polyvinyl butyral (PVB) is a common film layer material for
laminates with glass layers. The PVB film has good adhesion and
optical properties. The material has a high polarity which attracts
water. EVA has the same problem. Furthermore, PVB is extremely soft
and tacky. Therefore, the PVB film must be used with a release or
liner layer. Otherwise the roller of PVB film will be hard to
unwind.
PRIOR ART
[0010] EP1524292 describes a method to crosslink silane-grafted EVA
with a hindered amine to be used in cables. The examples show fast
crosslinking at elevated temperatures, which implies moderate
crosslinking at ambient conditions.
[0011] EP2562768 describes a cable layer with a polyethylene with
hydrolysable silane group(s) and a silanol condensation catalyst
that is a secondary amine. The crosslinking speed is high and in
table 4 the crosslinking is immediate at elevated temperatures.
[0012] The general problem of the prior art is to find a fast as
possible crosslinking speed.
BRIEF SUMMARY OF INVENTION
[0013] The invention is a film comprising a polymer composition
[0014] a polymer of ethylene (a) with a comonomer with silane
group(s) containing units that are hydrolysable and [0015] at least
one additive (b), wherein the additive is an organic compound which
comprises at least one amine moiety wherein the film has a gel
content less than 10 wt % after 7 days at ambient conditions and a
gel content of at least 15 wt % gel content after 14 days at
100.degree. C., when measured as described in "Test methods".
[0016] Polymers are defined to have more than at least 1000
repeating units. The definition of polymer of ethylene is a polymer
with more than 50 wt % of ethylene monomer. The polyethylene can
further comprise alfa-olefines and comonomers with vinyl group(s)
and functional group(s) such as polar comonomers.
[0017] Silane group(s) that are hydrolysable mean that a silanol
condensation reaction can form covalent bonds with other silane
group(s). The silane group(s) can make covalent bonds with other
silane group(s) of the silane crosslinkable polymer and form a
network. The network degree can for example be measured by creep or
gel content. Another advantage of the silane group(s) is that the
polymer is compatible with the glass layer and a good adhesion will
be achieved. Since the silane group(s) are covalently bonded to the
polymer backbone they can't be enriched in for example the surface
of the film. The film will be more uniform and consistent, meaning
that the homogenous film will have no starting points for
delamination from other layers.
[0018] Gel content is a measure of the degree of the crosslinking
network. The method for measuring gel content is described in the
"Test method". A high gel content means a complete network is
formed including more or less the entire polymer composition. The
object of this invention is to make a film for a laminate with a
front glass layer with at least one layer made of the polymer
composition.
[0019] Gel content is a common method for measuring the
crosslinking degree of a polymer. In certain applications are creep
a more proper method to measure the high temperature properties.
Since this parameter is application specific and uncommon, the
property of gel content has been chosen.
[0020] Laminate assembly is made in several steps. First step is to
make a film comprising a base resin and proper additivation such as
antioxidants and further stabilisers such as process stabilisers,
metal deactivators, and especially UV stabilisers.
[0021] The film is usually made at a film producer and shipped to
the laminate assembler. The laminate is made by laminating the film
to make the laminate with a front glass layer with at least one
layer made of the polymer composition. It is essential that the
film that is to be laminated has a low gel content. Lamination
using a crosslinked film gives low adhesion, meaning that the
laminate will easily delaminate. It is essential that the
crosslinking takes part after the lamination.
[0022] The activity of an additive (b) comprising at least one
amine moiety is hard to predict. A person skilled in the art can
identify from a list of available additives, with the guidance that
the film shall have a gel content less than 10 wt % after 7 days at
ambient conditions and a gel content of at least 15 wt % gel
content after 14 days at 100.degree. C. a proper additive (b)
comprising at least one amine moiety. The activity is depending on
activity of the additive with at least one amine moiety, on the
type if silane group(s), moisture content, temperature, the polymer
composition and other additives.
[0023] In order to be able to laminate the film, it must be
non-crosslinked, i.e. has a gel content less than 10 wt % (defined
as non-crosslinked). The silanol condensation reaction is
non-active when it is not needed. If the laminate is installed in a
warm place, i.e. in a desert, the condensation reaction will kick
in. The material will be crosslinked and the creep properties will
be improved.
[0024] The invention is using an additive with at least one amine
moiety that condensate the silane group(s) extremely slow.
[0025] One advantage is that the system is dormant when not needed
and active when needed. If the laminate is exposed to high heat the
additive with at least one amine moiety will kick in and crosslink
the film.
THE INVENTION IN DETAIL
[0026] In one embodiment of the invention the film has a gel
content suitably less than 8 wt % after 7 days at ambient
conditions and more suitably less than 5 wt % after 7 days at
ambient conditions. Further the film has a gel content of at least
20 wt % after 14 days at 100.degree. C. and more suitably gel
content of at least 30 wt % after 14 days at 100.degree. C., when
measured as described in "Test methods".
[0027] The polymer of ethylene (a) with a comonomer with silane
group(s) containing units that are hydrolysable is suitably in an
amount of at least 80 wt % of the polymer composition more
suitably, more than 90 wt % of the polymer composition.
[0028] The polymer composition can contain a smaller fraction of
further polymer(s). It is essential that these polymer fractions
form one phase with the polymer of ethylene (a) with a comonomer
with silane group(s) containing units that are hydrolysable. If the
polymers are forming two or more phases the optical performance of
the polymer blend will deteriorate. Further polymer fractions are
usually added as master batches to additivate the polymer
composition.
[0029] In one embodiment of the invention the polymer of ethylene
(a) with a comonomer with silane group(s) containing units that are
hydrolysable has suitably a density of at least 900 kg/m.sup.3 and
more suitably a density of at least 910 kg/m.sup.3 and most
suitably a density of at least 920 kg/m.sup.3, suitably is the
density less than 960 kg/m.sup.3 or more suitably less than 950
kg/m.sup.3.
[0030] The polymer of ethylene (a) with a comonomer with silane
group(s) containing units that are hydrolysable can be made by
several conventional processes. The hydrolysable silane group(s)
may be introduced into the polyethylene by copolymerisation of e.g.
ethylene monomers with silane group containing comonomer(s) or by
grafting, i.e. by chemical modification of the polymer by addition
of silane group(s) mostly in a radical reaction. Benefits of
copolymerisation are that no polar peroxide residues or unreacted
vinyl silanes are present in the final article. This will make the
final product more uniform with better consistency and improved
quality. Storage stability of the copolymerised ethylene with vinyl
triethoxy silane and/or vinyl trimethoxy silane made in a high
pressure radical process is greatly improved compared to grafted
solutions. Another benefit is less handling of liquid vinyl silanes
which are flammable and have a strong odour. Further benefits are
less scrap, less scorch (premature crosslinking in extruder) and
longer production runs (less cleaning of extruders).
Copolymerisation is the preferred production process of the polymer
of ethylene (A) with silane group(s) containing units. The amount
of silane group(s) can be decreased compared to grafting while
retaining same adhesion. The reason for this is that all silane
group(s) are copolymerised while grafted polymer usually contains
unreacted silane with peroxide residues.
[0031] The polymer made by copolymerisation in a high pressure
radical process is referred to as low density polyethylene (LDPE)
if the polymer constitutes more than 50 wt % of ethylene monomers.
The polymer of ethylene (A) with silane group(s) containing units
suitably is a low density polyethylene containing silane
group(s).
[0032] High pressure radical process is produced at high pressure
by free radical initiated polymerisation (referred to as high
pressure (HP) radical polymerisation), optionally using a chain
transfer agent (CTA) to control the MFR of the polymer. The HP
reactor can be e.g. a well known tubular or autoclave reactor or a
mixture thereof, preferably a tubular reactor. The high pressure
(HP) polymerisation and the adjustment of process conditions for
further tailoring the other properties of the polyolefin depending
on the desired end application are well known and described in the
literature, and can readily be used by a skilled person. Suitable
polymerisation temperatures range up to 400.degree. C., preferably
from 80 to 350.degree. C. and pressure from 70 MPa, preferably 100
to 400 MPa, more preferably from 100 to 350 MPa. Pressure can be
measured at least after compression stage and/or after the tubular
reactor. Temperature can be measured at several points during all
steps.
[0033] Further details of the production of ethylene (co)polymers
by high pressure radical polymerization can be found i.a. in the
Encyclopedia of Polymer Science and Engineering, Vol. 6 (1986), pp
383-410 and Encyclopedia of Materials: Science and Technology, 2001
Elsevier Science Ltd.: "Polyethylene: High-pressure, R. Klimesch,
D. Littmann and F. -O. Mahling pp. 7181-7184.
[0034] In one embodiment no peroxide has been added in the polymer
composition. This embodiment requires that the hydrolysable silane
group(s) are introduced to the polymer of ethylene (a) with a
comonomer with silane group(s) containing units that are
hydrolysable by copolymerisation in a high pressure radical
process.
[0035] In one embodiment of the film the polymer composition is
free from dibutyltin dilaurate (DBTDL), dioctyltin dilaurate
(DOTDL), which are not environmental friendly and free from
compounds with sulphonic acids groups that are known to break down
additives comprising amine moieties.
[0036] The polymer of ethylene (a) with a comonomer with silane
group(s) containing units that are hydrolysable has an MFR.sub.2 of
0.1 to 50 g/10 min, suitably 0.5 to 30 g/10 min and most suitably
10 to 25 g/10 min.
[0037] The silane group(s) containing comonomer or compound as
silane group(s) containing units (b) the is a hydrolysable
unsaturated silane compound represented by the formula
R.sup.1SiR.sup.2.sub.qY.sub.3-q (I)
wherein [0038] R.sup.1 is an ethylenically unsaturated hydrocarbyl,
hydrocarbyloxy or (meth)acryloxy hydrocarbyl group, [0039] each
R.sup.2 is independently an aliphatic saturated hydrocarbyl group,
[0040] Y which may be the same or different, is a hydrolysable
organic group and [0041] q is 0, 1 or 2.
[0042] Special examples of the unsaturated silane compound are
those wherein R.sup.1 is vinyl, allyl, isopropenyl, butenyl,
cyclohexanyl or gamma-(meth)acryloxy propyl; Y is methoxy, ethoxy,
formyloxy, acetoxy, propionyloxy or an alkyl-or arylamino group;
and R.sup.2, if present, is a f wherein R.sup.1 is vinyl, allyl,
isopropenyl, butenyl, cyclohexanyl or gamma-(meth) acryloxy propyl;
Y is methoxy, ethoxy.
[0043] In one embodiment the polymer of ethylene (a) with a
comonomer with silane group(s) containing units that are
hydrolysable is made in a high pressure radical process, i.e. a low
density polyethylene. Another benefit from copolymerised polymer of
ethylene (a) with a comonomer with silane group(s) containing units
that are hydrolysable is that no spacer is present between the
carbon backbone of the polymer and the silane triethoxy group
and/or silane trimethoxy group, i.e. the silane atom directly is
bonded to the polymer backbone. The stereochemistry for a
copolymerised polymer is much more restricted due to lack of
spacers, in other words the silane group is more hindered.
Therefore positioning the condensation catalyst in the correct
position is more difficult. That would result in lower activity of
the condensation catalyst. This makes the crosslinking slower. In
all grafted systems it will be at least 2 carbon atoms between the
carbon backbone chain and the silane group(s) (spacers), which make
the system much more reactive. This means that for a grafted system
should a less reactive additive (b) with at least one amine moiety
be used. It should be selected after the criteria's that the film
has a gel content less than 10 wt % after 7 days at ambient
conditions and a gel content of at least 15 wt % gel content after
14 days at 100.degree. C.
[0044] In another embodiment of the invention the polymer of
ethylene (a) with a comonomer with silane group(s) containing units
that are hydrolysable is comprising further polar comonomers (c),
excluding comonomers with silane group(s) containing units that are
hydrolysable. The polymer of ethylene (a) with a comonomer with
silane group(s) containing units that are hydrolysable has suitably
a total amount of polar comonomers (c), excluding comonomers with
silane group(s) containing units that are hydrolysable is from 10
wt % to 30 wt %, suitably 15 wt % to 30 wt %.
[0045] Examples of polar comonomers (c) are: vinyl carboxylate
esters, such as vinyl acetate and vinyl pivalate, (meth)acrylates,
such as methyl(meth)acrylate, ethyl(meth)acrylate,
butyl(meth)acrylate and hydroxyethyl(meth)acrylate, olefinically
unsaturated carboxylic acids, such as (meth)acrylic acid, maelic
acid and fumaric acid, (meth)acrylic acid derivatives, such as
(meth)acrylonitrile and (meth)acrylic amide, and vinyl ethers, such
as vinyl methyl ether and vinyl phenyl ether. The polar ethylene is
produced by a high pressure radical process.
[0046] The polar comonomers (c), excluding silane group(s)
containing units, can suitably be selected from vinyl acetate (VA),
buthylacrylate (BA), methylacrylate (MA), methylmethacrylate (MMA)
& ethylacrylate (EA). The polar comonomers will affect the
activity of the additive (b), which comprises at least one amine
moiety. If the polar comonomers (c), are acidic in nature the
activity of additive (b), which comprises at least one amine moiety
will decrease. The overall performance of the system is the sum of
all components. Most suitable polar comonomers (c), excluding
silane group(s) containing are acrylates such as BA, MA, MMA and EA
more suitably MA and MMA.
[0047] In one embodiment the total amount of silane group(s) in the
polyethylene composition is from 0.1 wt % to 15 wt %, suitably 0.5
to 5 wt % and more suitably 0.5-2 wt %.
[0048] In another embodiment the additive (b) comprising at least
one amine moiety is a stabiliser. The nature of stabilisers for
polymers is that they increase the life length of the polymer
composition, i.e. prevent degradation of the polymer. Degradation
proceeds in radical mechanism, and will finally destroy the polymer
properties. Polyolefines are going through an ageing process.
[0049] Examples of stabilisers are antioxidants (AO), Metal
Deactivators (MD), UV absorbers and UV-stabilisers. AO are added to
give long term stability in finished product. They also contribute
to process-stability. MD is mainly used to protect from copper ions
and other metal ions. Polyolefines need to be protected against
UV-light. This can be done by pigments or by UV-stabilisers such as
HALS (hindered amine light stabilisers).
[0050] The UV initiated degradation reaction mechanism is very
similar to thermal oxidative degradation. This may indicate that
phenolic AOs also act as UV-stabilisers, but they do not. The
reason is that phenolic AOs are rather unstable towards UV-light.
HALS, on the contrary, are UV-stable antioxidants.
[0051] In one embodiment the additive (b) comprising at least one
amine moiety is a stabiliser, such as AO, MD, UV absorber or UV
stabiliser, most suitably UV stabiliser and/or absorber
(hereinafter referred as UV agent). If film for the layer in
laminates is exposed to UV-light and is transparent an UV agent is
required. This prevents the use of pigments and a high amount of UV
agent is required. The UV agent should be selected to be efficient
with the specific polymer composition. Therefore one objective of
this invention is using a high amount of UV agent in order to
crosslink the film by a condensation reaction. In the application
of a film layer in a laminate, the reactivity is important. The
film is made by a film producer and shipped to laminate maker. The
film shall be non-crosslinked until the film is laminated. And it
should be crosslinked with time after lamination. Since the UV
agent is required, it is a further advantage that this system is
dormant when not needed and active when needed. If the laminate is
exposed to high heat, the additive (b) comprising at least one
amine moiety will kick in and crosslink the film to get better
creep properties.
[0052] In one embodiment according to all above embodiments, the
additive (b) comprising at least one amine moiety suitably has a
molecular weight (Mw) above 300 and more suitably a Mw above 600.
It is commonly known that exudation is affected by the size of the
stabilisers, bigger molecule have lower migration rate. In this
embodiment the activity of the additive (b) with at least one amine
moiety shall be relatively small, this is reached by targeting
large molecules.
[0053] The polymer composition can have an UV agent and an
antioxidant is present in an amount of 0.1 wt % to 5 wt %, more
suitably 0.1 to 2 wt % and most suitably 0.2 to 1 wt %.
[0054] Suitably the UV agent is blend of at least two UV
stabiliser(s) and/or absorber(s).
[0055] In one embodiment is the additive (b) comprising at least
one amine moiety is a secondary amine.
[0056] In a preferred embodiment the additive (b) comprising at
least one amine moiety is added to the polyethylene composition
during film extrusion.
[0057] List of suitable AO are for example, but not exhaustive,
Irganox 1098 manufactured by BASF, Naugard 445, Naugard S A &
Naugard J manufactured by Chemtura, AgeRite MA, Vanox 12 &
Vanox ZMTI & AgeRite White manufactured by R. T.
Vanderbilt.
[0058] List of suitable MD are for example, but not exhaustive,
Irganox MD 1024 from BASF, Naugard XL-1 manufactured by Chemtura,
Eastman inhibitor OABH & EMD-9 manufactured by Eastman
Chemical, ADK STAB CDA-1 & ADK STAB CDA-6 manufactured by Adeka
cooporation.
[0059] List of suitable UV absorbers is for example but not
exhaustive Tinuvin 312 manufactured by BASF.
[0060] List of suitable UV stabilisers are for example but not
exhaustive, Tinuvin 123, CGL 074, Tinuvin 144, Tinuvin NOR 371,
Tinuvin 622, Tinuvin 765 & Tinuvin 770, Chimasorb 944,
Chimasorb 966, Chimasorb 2020 FDL, Univinyl 4050H & Uvinyl 5050
H manufactured by BASF, Cyasorb UV-3346, Cyasorb UV-3529 &
Cyasorb UV-3853 manufactured by Cytec, ADK STAB LA-52, ADK STAB
LA-57, ADK STAB LA-62, ADK STAB LA-63P, ADK STAB LA-67, ADK STAB
LA-68 & ADK STAB LA-81 manufactured by Adeka corporation,
Hostavin N 20, Hostavin N 30, Hostavin PR-31 manufactured by
Clariant, Lowlite 19 manufactured by Chemtura, Uvasorb HA 88 sold
by 3V, Uvasil 299 manufactured by Great Lake Chemical, Sanol
LS-2626 manufactured by Sankyo.
[0061] List of more suitable UV stabilizers are Tinuvin 622,
Tinuvin 770 & Chimassorb 944.
[0062] One embodiment of the invention relates a to process for
making a laminate in which a polymer composition according to any
previous embodiment is extruded as a film that has gel content less
than 10 wt % after 7 days at ambient conditions, when measured as
described in "Test methods", wherein the film is laminated without
any peroxide decomposition. Benefit is no polar peroxide residues
or unreacted vinyl silanes are present in the laminate. It is one
object of the invention to reduce liquid additives, such as silanes
and peroxides, as much as possible in the polymer composition. This
will decrease problems with for example exudation, meaning the film
made from the composition will be less sticky, odour less
(improving working conditions significantly) and improves shelf
life of the film as such. No residues can be enriched in boundaries
between layers in the laminate. This will reduce risk for bubbles
and delamination. Suitably the laminate has a gel content of at
least 15 wt % after 14 days at 100.degree. C. Suitably is the
additive (b) comprising at least one amine moiety is added to the
polyethylene composition during film extrusion.
[0063] In one embodiment the film is laminated at a temperature of
100.degree. C. to 180.degree. C., suitably 120.degree. C. to
160.degree. C.
[0064] One embodiment of the invention is a laminate with a front
glass layer with at least one layer that is made of a polyethylene
composition comprising [0065] (a) a polyethylene bearing
hydrolysable silane group(s) and [0066] (b) at least one additive,
wherein the additive is an organic compound which comprises at
least one amine moiety and wherein the polymer composition has
creep less than <10 mm at 100.degree. C., 24 h, with a
precondition of the creep sample of 7 days at 70.degree. C. , 95%
RH, when measured as described in "Test methods".
[0067] Suitably has the polymer composition has creep less than
<10 mm at 100.degree. C., 24 h, with a precondition of the creep
sample of 7 days at 70.degree. C. , 95% RH.
[0068] In a more suitable embodiment the laminate that has the
layer made of the polyethylene composition is free from peroxides
and tin. Peroxide free means that no peroxide has been added to the
polymer composition at any stage. Tin free means that no tin has
been added to the process at any stage independent on the oxidation
state of the tin.
[0069] Test Method
[0070] a) Melt Flow Rate
[0071] The melt flow rate MFR2 was measured in accordance with ISO
1133 at 190.degree. C. and a load of 2.16 kg for ethylene homo and
copolymers.
[0072] b) Density: The density was measured according to ISO 1183D
and IS01872-2 for sample preparation.
[0073] d) The content (wt % and mol %) of polar comonomer present
in the polymer and the content (wt % and mol %) of silane group(s)
containing units (preferably comonomer) present in the polymer
composition (preferably in the polymer):
[0074] Quantitative nuclear-magnetic resonance (NMR) spectroscopy
was used to quantify the comonomer content of the polymer in the
polymer composition.
[0075] Quantitative 1H NMR spectra recorded in the solution-state
using a Bruker Advance III 400 NMR spectrometer operating at 400.15
MHz. All spectra were recorded using a standard broad-band inverse
5 mm probehead at 100.degree. C. using nitrogen gas for all
pneumatics. Approximately 200 mg of material was dissolved in
1,2-tetrachloroethane-d2 (TCE-d2) using
ditertiarybutylhydroxytoluen (BHT) (CAS 128-37-0) as stabiliser.
Standard single-pulse excitation was employed utilising a 30 degree
pulse, a relaxation delay of 3 s and no sample rotation. A total of
16 transients were acquired per spectra using 2 dummy scans. A
total of 32 k data points were collected per FID with a dwell time
of 60 .mu.s, which corresponded to to a spectral window of approx.
20 ppm. The FID was then zero filled to 64 k data points and an
exponential window function applied with 0.3 Hz line-broadening.
This setup was chosen primarily for the ability to resolve the
quantitative signals resulting from methylacrylate and
vinyltrimethylsiloxane copolymerisation when present in the same
polymer.
[0076] Quantitative 1H NMR spectra were processed, integrated and
quantitative properties determined using custom spectral analysis
automation programs. All chemical shifts were internally referenced
to the residual protonated solvent signal at 5.95 ppm.
[0077] When present characteristic signals resulting from the
incorporation of vinylacytate (VA), methyl acrylate (MA),
butylacrylate (BA) and vinyltrimethylsiloxane (VTMS), in various
comonomer sequences, were observed (Randell89). All comonomer
contents calculated with respect to all other monomers present in
the polymer.
[0078] The vinylacytate (VA) incorporation was quantified using the
integral of the signal at 4.84 ppm assigned to the *VA sites,
accounting for the number of reporting nuclie per comonomer and
correcting for the overlap of the OH protons from BHT when
present:
VA=(I*VA-(IArBHT)/2)/1
[0079] The methylacrylate (MA) incorporation was quantified using
the integral of the signal at 3.65 ppm assigned to the 1 MA sites,
accounting for the number of reporting nuclie per comonomer:
MA=I1MA/3
[0080] The butylacrylate (BA) incorporation was quantified using
the integral of the signal at 4.08 ppm assigned to the 4 BA sites,
accounting for the number of reporting nuclie per comonomer:
BA=I4BA/2
[0081] The vinyltrimethylsiloxane incorporation was quantified
using the integral of the signal at 3.56 ppm assigned to the 1VTMS
sites, accounting for the number of reporting nuclei per
comonomer:
VTMS=I1VTMS/9
[0082] Characteristic signals resulting from the additional use of
BHT as stabiliser, were observed. The BHT content was quantified
using the integral of the signal at 6.93 ppm assigned to the ArBHT
sites, accounting for the number of reporting nuclei per
molecule:
BHT=IArBHT/2
[0083] The ethylene comonomer content was quantified using the
integral of the bulk aliphatic (bulk) signal between 0.00-3.00 ppm.
This integral may include the 1VA (3) and .alpha. VA (2) sites from
isolated vinylacetate incorporation, *MA and .alpha. MA sites from
isolated methylacrylate incorporation, 1BA (3), 2BA (2), 3BA (2),
*BA (1) and .alpha. BA (2) sites from isolated butylacrylate
incorporation, the *VTMS and .alpha. VTMS sites from isolated
vinylsilane incorporation and the aliphatic sites from BHT as well
as the sites from polyethylene sequences. The total ethylene
comonomer content was calculated based on the bulk integral and
compensating for the observed comonomer sequences and BHT:
E=(1/4)*[Ibulk-5*VA-3*MA-10*BA-3*VTMS-21*BHT]
[0084] It should be noted that half of the a signals in the bulk
signal represent ethylene and not comonomer and that an
insignificant error is introduced due to the inability to
compensate for the two saturated chain ends (S) without associated
branch sites.
[0085] The total mole fractions of a given monomer (M) in the
polymer was calculated as:
fM=M/(E+VA+MA+BA+VTMS)
[0086] The total comonomer incorporation of a given monomer (M) in
mole percent was calculated from the mole fractions in the standard
manner:
M [mol %]=100*fM
[0087] The total comonomer incorporation of a given monomer (M) in
weight percent was calculated from the mole fractions and molecular
weight of the monomer (MW) in the standard manner:
M [wt
%]=100*(fM*MW)/((fVA*86.09)+(fMA*86.09)+(fBA*128.17)+(fVTMS*148.23-
)+((1-fVA-fMA-fBA-fVTMS)*28.05))
randall89
[0088] J. Randall, Macromol. Sci., Rev. Macromol. Chem. Phys. 1989,
C29, 201.
[0089] It is evident for a skilled person that the above principle
can be adapted similarly to quantify content of any further polar
comonomer(s) which is other than MA BA and VA, if within the
definition of the polar comonomer as given in the present
application, and to quatify content of any further silane group(s)
containing units which is other than VTMS, if within the definition
of silane group(s) containing units as given in the present
application, by using the integral of the respective characteristic
signal.
[0090] e) Gel content (wt %): is measured according to ASTM
D2765-90 using a sample consisting of said silane-crosslinked
polyolefin polymer composition of the invention (Method A, decaline
extraction). Ambient conditions is 23.degree. C., 50% room humidity
(RH). The RH at 50.degree. C. to 100.degree. C. was about 10%, if
not otherwise specified.
[0091] f) Creep
[0092] Films of 0.45 mm thickness were prepared from the sample.
Two samples of 30 mm * 120 mm were cut from the film. Two planar
surface glass slides of, 30 mm *150 mm * 3.85 mm thick, were washed
with isopropanol and dried were prepared. Two masks from Teflon
(0.1 mm thick) with a hole of 100 mm * 15 mm were also
prepared.
[0093] A creep test specimen was prepared having the structure
glass, mask, film, film, mask and glass. The glass slides were
positioned having an offset of 20 mm. The test specimen was vacuum
laminated at 150.degree. C., 300 seconds evacuation time, 660
seconds pressing time with 800 mbar membrane pressure. The Teflon
masks were preventing the polymer films to flow out, giving a well
specified width and length of the laminated film.
[0094] After lamination, the Teflon masks and excess film that had
not been in contact with the glass were removed. The test specimen
was marked with a distance of 75 mm, corresponding to zero creep.
The test specimen was inserted vertically in an oven, with
specified temperature, only supporting one of the glass slides. The
creep was measured as the distance relative to zero creep at
specified times, thereby obtaining the distance the test specimen
had moved during the test.
[0095] The creep can be seen as resistance to disposition at high
temperatures of the laminate.
EXAMPLES
[0096] Materials
[0097] EVS (2.1%) MA (26%) Terpolymer produced by a high pressure
tubular reactor in a conventional manner using conventional
peroxide initiator, with a max temperature of 285.degree. C., where
ethylene monomers were reacted with vinyl trimethoxysilane (VTMS)
and methylacrylate (MA) co-monomers amounts so as to yield 2.1 wt %
vinyl trimethoxy silane content and 26 wt % MA content in the
terpolymer. CTA was used to regulate MFR as well known for a
skilled person. The melt flow rate (MFR2@190.degree. C.) according
to ISO 1133 (190.degree. C., 2.16 kg) is 20 g/10 min and a melting
point of 85.degree. C.
##STR00001##
[0098] Compounding of the Blends
[0099] The different compounds were compounded on a pilot scale
extruder (Prism TSE 24TC). The obtained mixture was melt mixed in
conditions given in the table below and extruded to a string and
pelletized.
TABLE-US-00001 TABLE 1 Extruder setting for produced materials. Set
Values Temperatures (.degree. C.) Extruder Zone 1 Zone 2 Zone 3
Zone 4 Zone 5 Zone 6 rpm output pressure 120.degree. C. 140.degree.
C. 140.degree. C. 140.degree. C. 135.degree. C. 130.degree. C. 222
7.7 kg/h 55 bar
[0100] Film Sample Preparation:
[0101] Films (tapes) with a dimension of 50 mm width and 0.45 mm
thickness were extruded on a Collin teach-line E 20T extruder. The
tapes were produced with the following set temperatures:
[0102] 150/150/150.degree. C. and 50 rpm.
[0103] Results
TABLE-US-00002 TABLE 2 Results from creep test. Test was performed
at directly at 100.degree. C. Amounts of additives are given in
weight percentages. AO is 0.1 wt % Irgafos 168 and 0.5 wt % of
Irganox 1076. All are wt % Comp 1 Comp 2 Comp 3 Inv 1 Inv 2 Inv 3
Inv 4 Inv 5 Inv 6 EVS (2.1%) 100 99.4 99.4 98.9 98.9 99.2 98.9 99.2
98.9 MA (26%) AO 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 Chimassorb 0.5
0.25 0.1 0.25 0.2 944 Tinuvin 0.25 0.1 622 Tinuvin 0.25 0.5 770
Creep Fail 67 mm 12 mm 21 mm 38 mm 12 mm 100.degree. C., 24 h
[0104] Table 2 shows results from creep testing of EVS (2.1%) MA
(26%). The different samples have different UV-stabiliser and
concentrations. The results after 24 h at 100.degree. C. shows that
the creep performance above the terpolymer melting point is
improved by the addition of an amine moiety as a base catalyst for
silane crosslinking even though the creep specimens have not been
subjected to any preconditioning, meaning gel content is <1 wt
%.
[0105] Creep specimens with films of Inventive Example 1 were
prepared and subjected to preconditioning at 70.degree. C., 95% RH.
The results from creep measurements in Table 3 show the effect of
amine moiety catalysed crosslinking on the creep resistance over
the polymer melting temperature.
TABLE-US-00003 TABLE 3 The influence of preconditioning at
70.degree. C., 95% RH on the creep resistance for Inventive Example
1. Days at 70.degree. C., Creep at 100.degree. C., 95% RH 24 h 0 12
mm 4 0 mm 7 0 mm 14 0 mm
TABLE-US-00004 TABLE 4 Results from gel-content measurements as a
function of temperature. Gel % 0 days Gel % 2 days Gel % 7 days Gel
% 14 days Comparative Example 3 Ambient <1 <1 <1 <1
50.degree. C. <1 <1 <1 <1 100.degree. C. <1 <1
<1 4 Inventive Example 5 Ambient <1 <1 <1 <1
50.degree. C. <1 <1 <1 <1 100.degree. C. <1 <1 19
39 Inventive Example 1 Ambient <1 <1 <1 <1 50.degree.
C. <1 <1 <1 <1 100.degree. C. <1 9 43 51 Inventive
Example 6 Ambient <1 <1 <1 <1 50.degree. C. <1 <1
<1 <1 100.degree. C. <1 <1 <1 36
[0106] From the results on gel-content measurements in Table 4 it
is seen that the addition of an amine moiety will catalyse
crosslinking. Especially the gel-content after 14 days at
100.degree. C. is significantly improved. This will improve the
creep resistance above the polymer melting temperature. At
50.degree. C. there is a low crosslinking activity even after 14
days. A low gel content is needed to maintain good adhesion to
various substrates.
CONCLUSION
[0107] By adding an amine moiety to a polymer of ethylene (a) with
a comonomer with silane group(s) containing units that are
hydrolysable, crosslinking takes place at elevated temperatures.
This will improve the creep resistance of the polymer of ethylene
(a) with a comonomer with silane group(s) containing units that are
hydrolysable over the melting point.
* * * * *