Note: Descriptions are shown in the official language in which they were submitted.
WO 95/01397 ~. 2~2353 PCTIUS94/07279
GLOSSY AND TRANSPARENT INK-PRINTABLE
POLYOLEFINIC FILM COMPOSITION
Backqround of the Invention
This invention relatesto polyolefinic polymer compositions having improved
properties. In particular, this invention relates to improving the receptivity or adhesion of
printing inks to the surface of shaped articles made from such polyolefinic polymer
compositions.
Polyolefinic polymers, in particular ethylene polymers such as polyethylene are
used for forming shaped articles such as sheets, films, tubes, bottles, containers, etc. therefrom.
However, polyethylene has, and consequently articles made thereof have, an extremely smooth
hydrophobic surface which is unreceptive to most common types of printing inks and dyes and
thus it is difficult to print the surface of polyethylene articles.
Various known methods have been used to make ethylene polymers more
receptive to printing inks. For example, there are a number of surface treating techniques
which have been developed to improve the receptivity of the polymer surface to printing inks
including chemical treatment with oxidizing agents such as chlorine and strong acids and
electronic, or corona discharge treatment of the polymer surface. Flame treatment of the
surface of polyethylene has also been used to make the polyethylene more receptive to
20 printjng inks.
Another method used to improve the receptivity of the polymer surface to
printing inks is to apply a coating or printable top layer on the surface of the polymer layer to
beDrinted. Forexample,multilayerfilmshavebeendisclosedinthepriorartwhereinthetopprintable layer or printable skin layer of the film is described as being made from materials such
25 as ethylene acrylic acid, ethylene methyl acrylic acid, ethylene ethyl acrylate, ethylene methyl
acrylate, acrylonitrile butadiene styrene, nylon, polybutylene, polystyrene, polyurethane,
poiysulfone, polyvinylidene chloride, polypropylene, polycarbonate, polymethyl pentene,
styrene maleic anhydride, styrene acrylonitrile, ionomers based on sodium or zinc salts of
ethylene/methacrylic acid, acrylics, cellulosics, fluoroplastics, nitriles and thermoplastic
30 polyesters.
Still ar,vll ,er method used to improve the recepli~; Ly of a polymer surface toprinting inks is to form a novel poly,.,eric composition which has as one of its improved
properties an enhanced receptivityto printing ink. Thus, articles, such as a monolayer film,
made from said co",po,ilion would have the improved prope. ly of enhanced receptivity to
35 printing ink. For example, it is known to obtain an ethylene polymer co"-posilion having
excellentreceptivitytoprinting inksaftersurfacetreatmentbyincor~o~dlin9 intheethylene
polymer an N-substituted unsaturated carboxylic amide. It is also known to blend together a
mixture of commercially available, high molecular weight polyethylene with a minor but
WO 95/01397 - - PCT/US94/0727g
Z1423~3
effective amount of an oxidized, low molecular weight, polyethylene wax to form a plastic
molding composition and shaping the composition into an article by any of the known
cG"""ercial methods, which article has a surface which is hydrophilic and receptive to printing
i nks. Furthermore, polyolefi n compositions havi ng improved adhesion to water based inks
5 have been made by incorporating into the polyolefin an effective amount of a lactamide. '.
It is desired to provide yet another novel polymeric composition having enhancedreceptivity to printing ink by blending together an ethylene polymer with an effective amount
of an ink printability enhancing agent.
Anobjectofthepresentinventionistoimpartthedesiredprintabilityand
adhesion to printing inks to polyolefin compositions without adversely affecting the optical
properties of the polyolefin.
Summary of the Invention
One aspect of the present invention is directed to a composition which can be
used to make a film that combines exceilent printability with excellent optical prope. lies. The
compGsilion is obtained by blending into a polyolefin a minor portion of a polymeric additive
which does not deteriorate the optical p(ope- lies of the polyolefin.
The co,..pG,ilion of the present invention includes a polyolefin material with apol~..,e. ic additive having double bonds or having double bonds and a polystyrene present in
its chemical structure; or an anhydride modified polyolefin.
Another aspect of the present invention is directed to a film made of the above
composition.
Still another aspect of the present invention is preparing a film including the steps
of
(a) forming the composition;
(b) making a film from the composition; and
(c) applying an electrical discharge treatment to at least one of the surfaces of the
film.
Brief Descriotion of the Drawinqs
Figure 1 is an enlarged partial cross-sectional view of one embodiment of a film30 structure of the present invention.
Figure 2 is an enlarged partial cross-sectional view of another embodiment of a
film structure of the present invention.
Figure 3 is an enlarged partial cross-sectional view of one embodiment of a
prffsure-sensitive adhesive film structure useful for making labels in accordance with the
35 present invention.
Figure 4 is an enlarged partial cross-sectional view of another embodiment of a
pressure-sensitive adhesive film structure useful for making labels in accordance with the
present invention.
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wo gS/OL3g7 . ~-;214~353 PCTIUS94/07279
Detailed Descri ~ti on of the ~ efe. ed Embodiments
In its broadest scope the composition of the ~Dresent invention i ncl udes a
polyolefinic polymer and a polymeric additive refe"èd to herein as an "ink printability
enhancer" ("IPE"~.
The polyolefinic polymer includes for example low-density polyethylene (LDPc),
linear low density polyethylene (LLDPE), medium density polyethylene (MDPE), a high-density
polyethylene (HDPE), polypropylene (PP), propylene-ethylene copolymers, or mixtures of such
materials or mixtures which contain such materials. To the polyolefinic polymer material is
added the IPE polymeric additive.
The IPE is selected from a material which, in general, contains double bonds or
double bonds and a polystyrene in the IPE's chemical structure or an anhydride modified
polyolefin. Also, the IPE should not adversely affect the optical properties of composition. For
example, the IPE should not increase haze by more than 5 percent (absolute units) as measured
according to ASTM D-l 003 and/or should not decrease the 60 degree gloss by more than S
percent (absolute units) as measured according to ASTM D-2457.
Preferably, the IPE is selected from the group comprising styrenic block
copolymers, modified poly¢ '~rins and polyolefin poly...~., containing some degree of
unsaturation or mixtures thereof. The styrenic block copoly.-,o~, used as the IPE in the present
invention include, for eAa~ 'e, styrene-isoprene-styrene (SIS), styrene-butadiene-styrene (SBS)
20 of a grade having lower than 40 weight percent styrene, styrene-ethylene-butylene-styrene
(SEBS), styrene-isoprene (Sl), SlS/styrene-isoprene blend compositions and mixtures thereof.
The polymeric polyolefins using some degree of unsaturation include, for example,
polybutadiene, ethylene-propylene-diene copoly,..er, (EPDM), poly'isop-ene,
transpolyoctenamer and mixtures thereof. The modified polyolefins include, for example,
25 anhydride modified polyethylenes such as maleic anhydride containing olefin polymers and
copolymers such as those polymers commercial Iy available under the trademark ADMER~
(trademark of Mitsui P~t~ u.l,e. "icals) and styrene maleic anhydride and mixtures thereof. The
p. efer- ed IPE used in the prffent invention is SIS or mixtures containing SIS.In the composition, the IPE is present in an amount of from 3 weight percent to 50
30 weight percent, preferably from 5 weight percent to 30 weight pefcént; and more preferably
from 7 weight percent to 25 weight percent, with the remainder of the co...posi Lion being the
polyolefinic poly.-.er, that is, the composition generally contains from'50 weight percent to 97
weight percent, prëfel ably from 70 weight percent to 95 weight pefcenl, and more preferably
from 75 weight percent to 93 weight percent polyolefin.
Otheradditivescanalsobeblended intothecc......... posilion. Otheroptional
additivesthatcanbeaddedtotheco--,pû,ilionofthepresentinventionincludeforexample,antioxidants, antiblocks, antistatic additives, processing aids, inorganic fillers, UV stabilizers,
slip additives and pigments.
-3-
WO 95/OL397 ~4Z;~53 PCTtUSg4/07279
The amount of optional additive that can be used in the present composition willvary depending on the properties desired and effect desired. Usually one or more optional
additives may be present in the composition in an amount of from 0.00 1 weight percent to 15
weight percent for each additive individually. For exampie, when a nucleator or clarifying
5 agent is used, the composition can include from 0.1 to 0.5 weight percent of the nucleator ~r
ciarifying agent. If, for example, a lower gloss prope. ly is desired but still maintaining ink
printability, a filler such as calcium carbonate, talcum, silicon dioxide, chalk or other filler may
be used, and the amount can be from 1 to 6 weight percent. If, for example, transparency is
not desired, a pigment may be used in an amount of from 0.1 weight percent to 15 weight
10 percent and still maintain the property of ink printability. Processing aids that may be blended
in the composition may include, for example, Viton~ from Du Pont, Dynamar~ from 3M or
Ucarsil~ PA from Union Carbide which are all preferably added below 1 weight percent.
The polyolefin, IPE and other optional additives can be blended by well known
techniques into the art such as by tumble blending or separately feeding into an extruder
1 5 hopper.
The cG."posilion of the present invention can be used to make several forms,
including, for example, film, sheet orshaped articles by known pfocesses. For making shaped
articles, the processes include, for example, blow molding, compression molding, and injection
molding. For sheet and film manufacture, extrusion processes such as cast or blow pnxesses
20 may be used. In Modern Plastics Encyclopedia, 1969-70 edition, sheet is defined (page 52C) as a
flat section of a ll,e-",oplastic resin with the length considerably greaterthan the width and 10
mils or greater in thickness. Film is defined (page 43) as an optional term for sheet having a
nominal thickness notgreaterthan 0.010 inches. As an illustration of the present invention, a
monolayer film and a multilayer film product will be described herein below using the
25 composition of the present invention.
A monolayer film can be made by various con~cnlional film forming processes
including for example, a cast film process, a blown film process, oriented film process and other
extrusion processes or coating p~ ocesses. A multilayer film may be made by processes
c~",i"only used for manufacturing a multilayer film including, for example, coextrusion,
30 extrusion-coating, calendering and lamination. For making a multilayer film, coextrusion is
p.e~e"ed,becausethenthemultilayerfilmproductcanbeobtainedinonestep.
While the co.,.po,ilion of the present invention can be used to make a monolayerfilm, the present invention will be des~,ibed herein with reference to a multilayer film, a
p,efer-ed embodiment of the present invention. In its broadest scope the multilayer film
35 comprises a coextruded film structure containing at least one of its external or outer layers
madeofthecG...posilionofthepresentinvention. AnyfilmstructuresuchasA/B,AtB/Aor
A/B/C layered structures is possible, provided that at least one of the outer layers or skin layers
of the multilayer film is made of the present composition.
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wo gS/01397 Xi~23~;3 PCT/USg4l0727g
In Figure 1, there is shown a tvvo-layer film 10, comprising an outer layer 1 1 made
of the blend composition of the present invention and an inner adjacent layer 12 of one or
more polymers. Layer 12 can be made of any polymer resin which will adhere to the outer layer
11 including, for example, EVA, EAA, EMA, EMAA, EBA, ionomers, modified polyolefins, and
5 polyolefin materials such as LDPE, MDPE, HDPE, LLDPE, PP or blends thereof. .
One of the advantages of using the composition of the present invention as one
of the layers in a film structure (layer 11 in Figure 1), is the recyclability of the layer. Any
regrind, scrap or unused excess material can be reprocessed by reintroducing the material, as
recycle, back into the layer made of the present composition or back into another layer of the
10 film without significantly affecting the properties of the film. When recycle material is used,
generally from one percent by weight to 50 percent by weight of the recycle material can be
added back into the layer.
With, efe-ence to Figure 2, there is shown one p. erer, ed embodiment of a
multilayer film structure 2û of the present invention, in this case a three-layer structure,
15 including two outer layers or skin layers 21 with a core layer 22 sandwiched between the t~,vo
skin layers 21.
The skin layers 21 are made of the aforementioned composition of the present
invention. The core layer 22 can be made of any of the same resins for layer 1 1 and p, ~ te, ably a
polyolefin material such as LDPE, MDPE, HDPE, LLDPE, PP or blends thereof.
Also, any of the aforementioned optional additives used for the composition of
layer 1 1 can be used in any of the other layers 12 or 21 of the film.
The overall thickness of the film of the present invention can be from 5 microns to
200 microns, prere,ably from 50 to 150 microns. P(ererably~ the skin layer is from 2 percent to
25 percent of the total thickness of the film, preferably from S percent to 20 percent of the
25 total thickness of the film
Optionally, at least one of the surfaces of the film, intended to be printed, istreated by a corona discharge treatment to bring the film's surface tension above 40 milli
newton per meter (mN/m), p- eferably above 50 mN/m as measured according to ASTM D-2578
The corona discharge treatment is applied to at least one surface of the film. The corona
30 discharge treatment is well known in the art and described for example in surface prope, ~ies
andtesting,Plastics&~oly."~.s,April 1969,pages138-142. Whilecoronatreatment,alone,
increasesthesurfacetensionofthefilmlayertreatedtoimprovethespreadingoftheinkon
the film surface, it is believed thatthe composition of the present invention, in conjunction
with corona l,edlment or any other surface treatment of the film, further advantageously
35 enhancff the adhesion of the ink on the film without significant loss of optical prope, lies of
the film.
In accordance with another embodiment of the present invention, the monolayer
or multilayer films can be used as stock material for manufacturing labels, signs, displays, tags,
_5_
wo gS/0~ 14~53 PCT/US94/07279
posters, stickers. For ex3m`plë, the film label stock can be used for making in-mold labels,
pressure-sensitive labels and wrap around labels, sleeves and shrink sleeves.
One embodiment of this invention of particular interest relates to polyolefinic
films useful for making glossy, or glossy and transparent, and ink-printable pressure-sensitive
5 labels. The clear polyolefinic films made of medium to high density polyethylene fiim and
pressure-sensitive labels made from polyethylene film are typically used in labeling bottles.
While it is known to produce labels of polyolefins films, as aforementioned, thepoor printability of the polyolefin fil m usually requi res the application of an ink-pri ntable layer
on top of the polyolefin film to impart improved printability to the polyolefin film.
Multilayered label films are commonly produced by coating a poiyolefin film with an
ink-printable acrylic polymer, or coextruding or laminating the polyolefin film with a layer of
ink-printable polymer. The composition of the present invention can be used to produce in
one step polymeric films based on olefinic polymerswithout use of a top coat or ink printable
layer. A monolayer film made from the present composition provides excellent printability
without a significant loss of other fi l m prope~ lies such as optical properties such as low haze
and high gloss.
While a monolayer film can be produced from the cc.-,-posilion of the present
invention, for economical reasons, a pref~- ed embodiment of the present invention is to make
a multilayer film wherein one of the outer layers or skin layers of the film is made of the
20 CG---pG~i lion of the present invention.
A pressure-sensitive film stock 30 is illustrated i n Figure 3 which i ncludes a single
skin layer 11 on the outer side of a core layer 12 and a pressure-sensitive adhesive layer 31
directlyadjacenttheinnersideofthecorelayer 12. Thepressure-sensitiveadhesiveusedfor
layer 31 may be any conventional pressure-sensitive adhesive such as acylic and styrene
25 butadiene. The film stock 30 is preferably used for the manufacture of pressure-sensitive
labels.
Figure 4 shows another embodiment of a multilayer pressure-sensitive film stock
40includingtwoskinlayers21withacorelayer22andanadhesivelayer31 attachedtoatleastone of the skin layers 21.
In carrying out the process for making the film of the present invention,
generally,firstafilmcGI~posilionisformedwhereinthecc"~posi~ioncc."~p~isesatleastone
polyolefinmaterialandatleastonepolymericadditivewhichenhancestheinkprintability
property of the composition while not adverseiy affecting the optical properties of the
cc",.posilion. Then, a film from the composition is formed, for example, by coextrusion
35 techniques. An electrical discharge treatment may be applied to at least one surface of the
resultant film to raise the surface tension of the resultant film.
Asafo(elllelllioned~ with the use of a skin layer utilizing the composition of the
present invention, the ink printability of a multilayer film is enhanced. The skin layer of the
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WO 95/01397 ' ~ PCTIUS94/07279
-- ;~14235~3
multiiayer film can be printed with various printi ng systems. For example, print techniques
useful herein, include silk screen printing, rotogravure, letter press, offset, flexographic
printing, stipple printing, cold fixing laser printing, copperplate printing.
Various types of inks can also be selected for use in the present invention
5 including, for example, one and two component inks, oxidatively or UV-drying inks, dissolve .
ordispersedor lOO% inksystems. Manycombinationsoffilm/printing,ink/printingtechniques
are possible.
General Procedure
In the Examples which follow, the general procedure used to manufacture the
10 film of the present invention is as follows:
Charge"l"ofafilmformingresinispreparedcomprisingXweightpercentofa
polymeric resin re ~e~ ,ed to below as Resin A", Y percent of a polymeric additive referred to
below as Additive B" and Z percent of one or more polyolefin resins refe. ed to below as .
Resin Co",po,iLion C".
Then Charge "Il" of a film forming resin composition comprising one or more
polyolefin resins is prepared.
Both the "I" and ll" Charges are fed into extruders and coextruded to form a
three-layered film with a l/ll/l layer structure. The total thickness of the film structure is T and
the thickness of each layer of Charge I is T1.
An elerical "coronan discharge treatment is applied on one or both surfaces of
the film to raise its surface tension.
The resulting film has excellent optical properties (similar haze and gloss as films
consisting essentiallyof polyolefin), and hasexcellent ink-printabilitywithoutthe need to add
any substrate onto the film's surface.
For econo",ical or practical reasons, it is prefe,c.ble to produce a multilayer film
with the Charge I being at least one of the skin layers, but monolayer films comprising only the
Charge I can also be made.
The following co",po,i Lions and conditions were tested.
ExamPle 1
A coextruded three-layer film having a l/ll/l layer structure was manufactured
according to the above General Procedure. Charge I i ncl uded Resi n A, Additive B and Resin
CGIIIPO~; ~ion C.
Resin A was 7 weight percent of a styrene-isoprene-styrene copoly. "er (SIS)
having a melt index (Ml) of 9.0 grams per 10 minutes (9/10 min) (200 degrees centigrade (0)/5
35 kilograms (kg)) and containing 85 weight percent of polymerized isoprene.
Additive B was 5 weight percent of a 15 weight percent silicon dioxide
masterbatch in a low density polyethylene (LDPE).
WO 95/01397 2i42353 PCT/USg4l0727g
Resin Composition C was 10 weight percent of a high density polyethylene (HDPE)
having a density of 0.955 gram per cubic centime~er (g/cm3) and a Ml of 4.0 g/10 min
(190C/2.16kg).
The balance to 100 percent for Charge i was a LDPE having a density of 0.921
g/cm3 and a Ml of 3.5 9/l O min (190C/2.16 kg).
Charge ll of the film structure compnsed 80 weight percent of a HDPE having a
densityofO.955g/cm3andaMlof4.0g/lOmin(190C/2.16kg);and20weightpercentofa
LDPE having a density of 0.923 g/cm3 and a Ml of 1.75 9/l o min (190C/2.16 kg).A film having a of thickness of 90 micrometers of a l/ll/l layer structure was
1O produced by a cast coextrusion process using Charges I and ll described above. The thicknesses
(Tl) of the external layers (Charge 1) was 10 micrometers each.
One surface of the film was treated by a "corona" discharge treatment to bring
its surface tension above 50 mN/m.
The optical properties of the film is shown in Table 1. The percent gloss
measurement of the film was measured in accordance with ASTM D-2457 and the percent haze
measurement was measured in accordance with ASTM D- 1003.
The film produced in this Example 1 was printed on the corona treated side usingUV curable inks on flat bed silk screen printing equipment.
The adhesion of the ink on the film was tested using the following four ink
20 adhesion tests:
(1) adhesive tape test,
(2) scratch . esislance on the dry film,
(3) scratch resistance after immersion of the film for 4 hours in a 50/SO volumepercent solution of water plus shampoo at room te."pe(alure (22C), and
(4) scratch rësi,ldnce after immersion of the films for 22 hours in a SO/50
volume percent solution of water plus shampoo at room temperdlure
(22C).
The afo, el l ,e"lioned adhesive tape test is descri bed as follows: A 15 mm wide
piece of self adhesive tape is pressed onto the surface of the printed area of a film sample. This
30 is then rapidly pulled away from the film. The percer,lage of ink rc,..o/ed from the sample by
the tape is cc,..,paræd. The amount of ink is visually compared and a numerical rating of " 1 to
4" is given to the fil m samples wherein " 1 is the lowest amount of ink remaining on the tape
and .,4u being the grealesl amount of ink remaining on the tape.
The afc, e",enlioned scratch resi~lance test is described as follows: A film label
35 sample is adhered onto a stiff surface. The printed surface of the film is manually rubbed with
a metal spatula. The difficulty or ease of scratching the ink is rated as follows: 1 " not
scratchable, 2" sc(at-hable with difficulty, "3 scratchable, "4" easily scratchable, 5"
WO 5SI~ 7 Z14Z353 PCT/US94/07279
scratchable by touching. This test is ~erformed on the dry film or on the wet film after
immersion in the solutions described above.
The results of the above ink adhesion tests are listed in Table 11.
Example 2
A three-layer coextruded film having a 1/11/1 layer structure was manufac~ured .nd
tested following the procedure of Example 1. The Charges I and 11 were the same as in Example
1 except that Resin A was 14 weight percent SIS having a of 9.0 9/l O min (200C/S kg) and
containing 85 weight percent of polymerized isoprene. The optical properties of the resultant
film are shown in Table I and the results of the adhesion tests are listed in Table 11.
Example 3
A three-layer coextruded film having a 1/11/1 layer structure was manufaured and
tested following the procedure of Example 1. The Charges I and 11 were the same as in Example
1 except that Resin A was 25 weight percent Admer~ L 2000 resin, a polymeric resin containing
around 0.6 weight percent of grafted maleic anhydride and commercially available from Mitsui
Petrochemicals. The optical properties of the resultant film are shown in Table I and the results
of the adhesion tests are listed in Table 11.
Comparative Example A
A three-layer coextruded fil m having a 1111/1 layer structure was manufactured and
tested following the procedure of Example 1. The Charges I and 11 were the same as in Example
20 1 except that no Resin A was used in this Example. This comparative example was used as the
Control. The optical p~o~e, lies of the Control is shown in Table I and the results of the
adhesion tests are listed in Table 11.
Co",~a,d~ Examnle B
The adhesion tests described in Example 1 were carried out on a pure
25 polyethylene film coated with an acrylic coating (Comparative Example B). The results are
listed in Table 11.
TABLE I
60 Degree Gloss Haze
Film (%) (Z)
30 Co~trol 80 18
(Comparative Example A)
Example 1 85 19
Example 2 85 17.5
Example 3 81 18
WO 95/OL397 PCT/US94/07279
214Z353
. ., ~ ~
. ~ " ~ ~ ,.....
C ;l
o ~,
X
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E
X
~ ~ C~l C~
X
E
' G 0
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c~ F X
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~! D
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,~ - . C O C-0'3
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a~
O ~ ~ o ~ U ~ ~
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WO 95/OL397 . i ` ~ PCT/US94/07279
` 2~42353
Tabie I shows that the oDtical properties of Examples 1 2 and 3 are simiiar to that
of the Controi film.
From the results shown in Table ll films from Exam~les 1 2 and 3 pe, ior", as well
as the film of Comparative Example B and far better than the Control film.
5 ExamDle 4
A three-layer coextruded film having a l/ll/l layer structure was manufactured
according to the above General Procedure. Charge I included components Resin A Additive B
and Resin Composition C.
ResinAwas12weightpercentofSlShavingaMlof9.0g/10min(200C/5kg)and
10 containing 85 weight percent of polymerized isoprene.
Additive B was S weight percent of a 15 weight percent silicon dioxide
masterbatch in a LDPE.
Resi n Co" ,posi lion C was 10 wei ght percent of a HDPE having a density of 0.965
g/cm3and a Ml of 8.09/10 min (190C12.16kg).
The balance to 100 percent for Charge I was a LDPE having density of 0.923 g/cm3and a Ml of 1.75 9/10 min (190C/2.16 kg).
Charge ll of the film structure co",p-ised 70 weight percent of a HDPE having a
densityO.965g/cm3andaMlof8.0g/10min(190C/2.16kg); and20weightpercentofa LDPE
having a density of 0.922 g/cm3 and a Ml of 1.2 g/10 min (190C12.16 kg).
A fiim having a thickness of 90 micrometers of a l/ll/l layer structure was produced
by a cast coextrusion process using Charges I and ll described above. The thicknesses (T1) of the
external layers (Charge 1) was 10 micrometers each.
One surface of the film was treated by a 'corona discharge treatment to bring
its surface tension above 50 mN/m.
The optical prope, lies of the film are shown on the following Table lll. The
percent gloss measurement of the film was measured in accordance with ASTM D-2457 and the
percent haze measurement was measured in accordance with ASTM D-1003.
ExamPle S
A three-layer coextruded film having a l/ll/l layer structure was manufactured and
30 tested following the procedure of Example 4. The Charges I and ll were the same as in Example
4 except that there was no Additive B in Charge 1. The optical properties of the resultant film
are shown in Table lll.
Examole 6
A three-layer coextruded film having a l/ll/l layer strunure was manufactured and
35 tested following the procedure of Example 4. The Charges I and ll were the same as in Example
4 except that Resi n A was 12 weight percent of a styrene-isoprene-styrene/styrene-isoprene
copolymers blend (SIS/SI) having a Ml of 10.0 9/10 min (200C15 kg) and containing 85 weight
WO 95/01397 Z1423S3 PCT/uS94l0727g
.
percent of polymerized isoprene. The SIS/SI ratio of the blena was 82/18 percent. The optical
properties of the resultant film are shown in Table ill.
ExamDle 7
A three-layer coextruded film having a l/ll/l layer structure was manufactured and
tested following the procedure of Example 4. The Charges 1 ana ll were the same as in ExaQ ple
4 except that Resin A was 12 weignt percem of SIS having a Ml of 12.0 9/lO min (200C15 kg)
and containing 82 weight percenl of polymerized isoprene. The optical properties of the
resultant film are snown in Table lll.
Exam~le 8
1 O A three-layer coextruded fi l m having a l/ll/l layer structure was manufactured and
tested following the procedure of Example 4. The Charges I and ll were the same as in Example
4exceptthatResinAwas 12weightpercentofSlShavingaMlof 13.0g/10min(200C/Skg)
and containi ng 70 weight percent of polymerized isoprene. The optical properties of the
resultant film are shown in Table lll.
Exam~ole 9
A three-layer coextruded film having a l/ll/l layer structure was manufactured and
tested fol lowi ng the procedure of Example 4. The Charges I and l l were the same as i n Example
4 except that Resin A was 12 weight percent of SiS having a Ml of 40.0 9/10 min (200C/5 kg)
and containing 55 weight percent of polymerized isoprene. The optical properties of the
20 resultant film are shown in Table lll.
WO 95/OL397 ~ PCTtUS94/07279
23~53
Com~arative ExamDle C
A three-layer coextruded film having a l/ll/l layer structure was manufactured and
tested following the Drocedure of Example 4. The Charges I and ll were the same as in Example
4 except that no Resin A was used in Charge 1. This comparative examDie was used as the
5 Control. The opticai pro,oertles of the Control are shown in Table lll.
TABLE III
60 Degree Gloss Haze
Film (%) (%)
Control 79 25
(Comparative Example C)
Example 4 83 22
Example 5 91 18
Example 6 85 20
Example 7 85 20
5 Example 8 85 21
Example 9 95 22
2û Table lll shows that the optical prope- lies of Examples 4-9 are similar to the
Control.
Comparative Examole D
A three-layer coextruded film having a l/ll/l layer structure was manufactured
according to the above General Procedure. Charge I included co",poner,l~ Resin A Additive B
25 and Resin CG,-,posilion C.
Resin A was 8 weight percent of a sytrene-butadiene-styrene copolymer (SBS)
having a Ml of 6.0 9/10 min (200C/5 kg) and containing 60 weight percent of polymerized
butadiene.
Additive B was 5 weight percent of a l S weight percent silicon dioxide
30 masterbatch in a LDPE.
Resin Composition C was 10 weight percent of a HDPE having a density of 0.955
g/cm3andaMlof4.0g/10min(190C/2.16kg).
The balance to 100 percent for Charge I was a LDPE having density of 0.921 g/cm3- andaMlof3.5g/10min(190C/2.16kg).
Charge ll of the film structure comprised 80 weight percent of a HDPE having a
density 0.955 g/cm3 and a Ml of 4.0 9/10 min (190C/2.16 kg); and 20 weight percent of a LDPE
having a density of 0.923 g/cm; and a Ml of 1.75 9/10 min (190C/2.16 kg).
WO gs/0l3g7 z~4z353 PCT/US94107279
A film having a thickrlès~ 5~ micrometers of a l/ll/l layer structure was produceci
by a cast coextrusion process using Charges I and ll descriDed above. The thicknesses (T1) of the
external layers (Charge 1) was 10 micrometers each.
One surface of the fi I m was treated by a "corona " discharge treatment to bri ng
5 its surface tension above 50 mN/m.
The opticai properties of the film is shown on the foilowing table IV. The percent
gloss measurement of the film was measured in accordance with ASTM D-2457 and the percent
haze measurement was measured in accordance with ASTM D- 1003
Comparative Example E
A three-layer coextruded film having a l/ll/l iayer structure was manufactured and
tested following the procedure of Example 10. The Charges I and ll were the same as in
Example 10 excep~that Resin A was 25 weight percent of a ethylene-acrylic acid copolymer
(EAA)havingaMlof 10.0g/10min(190C/2.16kg)andcontaining9weightpercentof
polymerized acrylic acid. The optical properties of the resultant film are shown in Table IV.
ComDarative ExamDle F
A three-l ayer coextruded film havi ng a l/l l/l layer structure was manufactured and
tested following the procedure of Example 10. The Charges I and ll were the same as in
Example 10 except that Resin A was Z5 weight percent of a ethylene-methyl acrylate copolymer
(EMA)havingaMlof3.0g/10min(190C/2.16kg)andcontaining 15weightpercentof
20 polymerized methyl acrylate. The optical prope, lies of the resultant film are shown in Table IV.
Comparative ExamDle G
A three-layer coextruded film having a l/ll/l layer structure was manufactured and
tested following the procedure of Example 10. The Charges I and ll were the same as in
Example 10 except that Resin A was 25 weight percent of a ethylene-butyl acrylate copolymer
25 (EBA)havingaMlof4.0g/10min(190C/2.16kg)andcontaining 17weightpercentof
polymerized methyl acrylate. The optical prope. Lies of the resultant film are shown in Table IV.
WO 95/OL397 ;~1~2353 PCT/US94/07279
ComDarative ExamDle H
A three-iayer coextruded film having a l/ll/l lay~r structure was manufactured and
tested following the procedure of Example 10. The Charges I and ll were the same as in
Example 10 except that Resin A was 25 weight percent of a sodium salt of an ethylene-
methacryllcacidcopoiymerhavingaMlof2.89/lOmin(190~C/2.16kg)andhavingadensitjof
0.94g/cm n Theoptical~ropertiesoftheresultantfilmareshownin T ableIV.
ComDarative Exam~le I
A three-layer coextruded film having a l/ll/l layer structure was manufactured and
tested following the procedure of Example 10. The Charges I and ll were the same as in
10 Example 10exceptthatResinAwas 15weightpercentofahutyl rubber. Theoptical properties
of the resultant film are shown in Table IV.
ComDarative ExamPle J
A three-layer coextrùded film having a l/ll/l layer structure was manufactured and
tested following the procedure of Example 10. The Charges I and ll were the same as in
Example 10 except that no Resin A was used in Charge 1. This comparative example was used as
the Control. The optical properties of the Control are shown in Table IV.
TABLE IV
Film 60 Degree Gloss Haze
Control 80 18
(Comparative Example J)
Example D 33 42
Example E 72 24
25 Example F 62 24
Example G 70 20
Example H 65 29
Example I 17 66
WO 95/01397 2142353 PCT~JS94/07279
Table IV shows that the optical properties of Comparative Examples D-l are worse(have lower gloss and higher haze~ than the Control film J.
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