(12) INTERNATIONAL APPLICATION PUBLISHED UNDER THE PATENT COOPERATION TREATY (PCT)
`(19) World Intellectual Property
`Organization
`International Bureau
`
`(10) International Publication Number
`WO 2014/005214 Al
`
`BZ, CA, CH, CL, CN, CO, CR, CU, CZ, DE, DK, DM,
`DO, DZ, EC, EE, EG, ES, FI, GB, GD, GE, GH, GM, GT,
`HN, HR, HU, ID, IL, IN, IS, JP, KE, KG, KN, KP, KR,
`KZ, LA, LC, LK, LR, LS, LT, LU, LY, MA, MD, ME,
`MG, MK, MN, MW, MX, MY, MZ, NA, NG, NI, NO, NZ,
`OM, PA, PE, PG, PH, PL, PT, QA, RO, RS, RU, RW, SC,
`SD, SE, SG, SK, SL, SM, ST, SV, SY, TH, TJ, TM, TN,
`TR, TT, TZ, UA, UG, US, UZ, VC, VN, ZA, ZM, ZW.
`
`(43) International Publication Date
`9 January 2014 (09.01.2014)
`
`P O P C T
`
`(51) International Patent Classification:
`B32B 27/08 (2006.01)
`B32B 27/32 (2006.01)
`
`(21) International Application Number:
`
`(22) International Filing Date:
`
`PCT/CA2013/000555
`
`11 June 2013 ( 11.06.2013)
`
`(25) Filing Language:
`
`(26) Publication Language:
`
`English
`
`English
`
`(30) Priority Data:
`61/668,293
`
`5 July 2012 (05.07.2012)
`
`US
`
`(71) Applicant: NOVA CHEMICALS (INTERNATIONAL)
`S.A. [CH/CH]; Avenue de la Gare 14, CH-1700 Fribourg
`(CH).
`
`(84) Designated States (unless otherwise indicated, for every
`kind of regional protection available): ARIPO (BW, GH,
`GM, KE, LR, LS, MW, MZ, NA, RW, SD, SL, SZ, TZ,
`UG, ZM, ZW), Eurasian (AM, AZ, BY, KG, KZ, RU, TJ,
`TM), European (AL, AT, BE, BG, CH, CY, CZ, DE, DK,
`EE, ES, FI, FR, GB, GR, HR, HU, IE, IS, IT, LT, LU, LV,
`MC, MK, MT, NL, NO, PL, PT, RO, RS, SE, SI, SK, SM,
`TR), OAPI (BF, BJ, CF, CG, CI, CM, GA, GN, GQ, GW,
`KM, ML, MR, NE, SN, TD, TG).
`Inventors; and
`(72)
`(71) Applicants : BORSE, Nitin [CA/CA]; 245 Silverado Declarations under Rule 4.17 :
`Plains Close S.W., Calgary, Alberta T2X 0G6 (CA). AU- — as to applicant's entitlement to apply for and be granted a
`BEE, Norman Dorien Joseph [CA/CA]; 32 Cimarron
`patent (Rule 4.1 7(H))
`Drive, Okotoks, Alberta T1S 1S8 (CA). WARD, Daniel R.
`[US/US]; 1159 Chaucer Place, Maineville, Ohio 45039 — as to the applicant's entitlement to claim the priority of the
`earlier application (Rule 4.1 7(in))
`(US).
`(74) Agents: CHISHOLM, P., Scott et al; 2928-16 Street NE, — of inventorship (Rule 4.17(iv))
`Calgary, Alberta T2E 7K7 (CA).
`Published:
`(81) Designated States (unless otherwise indicated, for every — with international search report (Art. 21(3))
`kind of national protection available): AE, AG, AL, AM,
`AO, AT, AU, AZ, BA, BB, BG, BH, BN, BR, BW, BY,
`
`oo
`o (54) Title: CURL RESISTANT BARRIER FILMS
`(57) Abstract: Multilayer "barrier" films which have excellent Water Vapor Transmission Rate (WVTR) performance are prepared
`using a core layer which comprises a blend of from 92 to 60 weight % of nucleated HDPE and from 8 to 40 weight% LDPE. The
`films are suitable for the preparation of packages for dry foods such as crackers and breakfast cereals.
`
`EPL LIMITED EX1007
`U.S. Patent No. 10,889,093
`
`0001
`
`

`

`CURL RESISTANT BARRIER FILMS
`
`This invention relates to new designs for multilayer plastic films having high
`
`TECHNICAL FIELD
`
`barrier properties.
`
`BACKGROUND ART
`Plastic films having gas barrier properties are widely used in packaging for dry
`
`foods. The films should have a low Water Vapor Transmission Rate (WVTR) and a low
`
`Oxygen Transmission Rate (OTR). Aroma barrier is also desirable.
`
`The paper packaging that was originally used in these applications was partially
`
`replaced by cellophane, but cellophane is expensive and difficult to process.
`
`Barrier films prepared from high density polyethylene (HDPE) offer an alternative
`
`to paper or cellophane. HDPE films offer a good balance between cost and
`
`performance. However, when additional barrier and/or toughness is required, it is
`
`known to prepare multilayer films which contain layers made of more expensive barrier
`
`resins (such as ethylene-vinyl alcohol (EVOH); polyamide (nylon); polyesters; ethylene-
`
`vinyl acetate (EVA); or polyvinyldiene chloride (PVDC)) and/or layers of
`
`stronger/tougher resins such as ionomers or linear low density linear polyethylenes
`
`("LLDPE"). Sealant layers made from EVA, ionomer, "high pressure low density
`
`polyethylene" ("LDPE") or plastomers are also employed in multilayer structures.
`
`The expensive barrier resins listed above (polyamide, EVOH, polyesters and
`
`PVDC) tend to be more polar than HDPE. This can cause adhesion problems between
`
`layers of polar and non-polar resins in multilayer film structures. Accordingly, "tie
`
`layers" or adhesives may be used between the layers to reduce the probability that the
`
`layers separate from one another.
`Monolayer HDPE films are inexpensive, easy to prepare and offer moderate
`
`resistance to water vapor and oxygen transmission. Moreover, it is simple to provide
`
`increased barrier properties by just increasing the thickness of the film. However, the
`
`mechanical properties (such as tear strength and impact strength) and sealing
`
`properties of HDPE film are comparatively low so multilayer films are widely used.
`
`Thus, the design of barrier films involves a cost/benefit analysis - with the low
`
`cost of HDPE resin being balanced against the better performance of the more
`
`expensive, polar resins. Another way to lower the cost of the film is to simply use less
`
`material - by manufacturing a thinner or "down gauged" film.
`
`0002
`
`

`

`Examples of multilayer barrier films that use HDPE are disclosed in United
`
`States Patents 4,1 88,441 (Cook); 4,254,169 (Schroeder); and 6,045,882 (Sandford)
`
`and our previously published Canadian patent application CA 2,594,472 (Aubee et al.).
`DISCLOSURE OF INVENTION
`
`The present invention provides:
`
`a barrier film comprising a core layer and two skin layers, wherein said core layer
`
`consists essentially of a blend of:
`
`a)
`
`b)
`
`from 60 to 92 weight% of a nucleated high density polyethylene resin; and
`
`40 to 8 weight% of high pressure, low density polyethylene.
`
`It will be appreciated by those skilled in the art of producing multilayer films that
`
`these films can roll up upon themselves or "curl." One generally accepted theory for the
`
`mechanism that causes curl is that "differential shrinkage" - i.e. the tendency for one
`
`layer to shrink at a different rate from the others - leads to curl. This theory has been
`
`discussed in the literature and is summarized in two papers that were presented at the
`
`annual conference of the Society of Plastics Engineers ("SPE") in 2002 (ref: Morris;
`
`SPE (2002), 60th (Vol 1), 40-46 and Morris; SPE (2002), 60th (Vol 1), 32-39).
`
`Two factors that may influence the degree of differential shrinkage are:
`
`1) The materials of construction (for example, if a skin layer is made from a
`
`material that shrinks more than the material used for an inner layer; and
`
`2) Process conditions: for example, if a freshly fabricated film is cooled on
`
`only one side of the film (such as the interior of a blown film), the rate of
`
`shrinkage on that side can be different from the rate of shrinkage on the
`
`"outside" of the blown film bubble.
`
`These problems can be increased when a nucleating agent is present in the
`
`material used in one layer of a multilayer film because in general, the addition of a
`nucleating agent will cause a polymeric material to shrink more upon cooling (in
`
`comparison to the rate of shrinkage for the same polymer under the same cooling
`
`conditions in the absence of the nucleating agent). To some extent, this problem can be
`
`mitigated by using the same nucleated polymer in the core layer and at least one of the
`
`skin layers. An example of this type of film design is disclosed in Table 1 of CA
`
`2,594,472. We have now discovered another design alternative that utilizes a blend of
`
`HDPE and LDPE in the core layer of a multilayer film.
`
`0003
`
`

`

`BEST MODE FOR CARRYING OUT THE INVENTION
`
`A .
`
`- HDPE
`
`Preferred HDPE for use in the films of this invention has a density of from 0.950
`
`grams per cubic centimeter (g/cc) to about 0.970 g/cc as determined by ASTM D1505.
`
`Preferred HDPE also has a density of greater than 0.955 g/cc and the most preferred
`
`HDPE is a homopolymer of ethylene having a density of greater than 0.958 g/cc.
`Preferred HDPE is further characterized by having a melt index, l2, of from 0.3 to 20
`grams per 0 minutes, especially from 0.5 to 10 grams per 0 minutes (as measured by
`ASTM D1238 at 190° C with a 2.16 kg load and commonly referred to as "l2")
`The molecular weight distribution of the HDPE [which is determined by dividing
`
`the weight average molecular weight (Mw) by number average molecular weight (Mn),
`
`where Mw and Mn are determined by gel permeation chromatography, according to
`
`ASTM D 6474-99] is preferably from 2 to 20, especially from 2 to 10.
`
`A highly preferred HDPE is prepared by a solution polymerization process using
`
`two reactors that operate under different polymerization conditions. This provides a
`
`uniform, in situ blend of two HDPE blend components. An example of this process is
`
`described in U.S. patent 7,737,220 (Swabey et al.), the disclosure of which is
`
`incorporated herein by reference. The use of the "dual reactor" process also facilitates
`
`the preparation of blends which have very different melt index values.
`
`It is highly
`
`preferred to use a blend (prepared by the dual reactor process) in which the first HDPE
`blend component has a melt index (l2) value of less than 0.5 g/1 0 minutes and the
`second HDPE blend component has an l2 value of greater than 100 g/1 0 minutes. The
`amount of the first HDPE blend component of these blends is preferably from 40 to 60
`
`weight % (with the second blend component making the balance to 100 weight %). The
`
`overall HDPE blend composition preferably has a MWD (Mw/Mn) of from 3 to 20.
`
`B .
`
`Nucleating Agents
`
`The term nucleating agent, as used herein, is meant to convey its conventional
`
`meaning to those skilled in the art of preparing nucleated polyolefin compositions,
`
`namely an additive that changes the crystallization behavior of a polymer as the
`
`polymer melt is cooled.
`
`Nucleating agents are widely used to prepare polypropylene molding
`
`compositions and to improve the molding characteristics of polyethylene terephthalate
`
`(PET).
`
`A review of nucleating agents is provided in USP 5,981 ,636; 6,466,551 and
`
`6,559,971 , the disclosures of which are incorporated herein by reference.
`
`0004
`
`

`

`The multilayer films of this invention comprise a core layer which must contain
`
`"nucleated HDPE". As used here, the term "nucleated HDPE" is meant to convey its
`
`plain meaning, namely HDPE (as described in Part A above) which contains a
`
`nucleating agent (as described in Part B).
`
`The nucleating agent is preferably well dispersed in the HDPE. The amount of
`
`nucleating agent used is preferably quite small - from 100 to 3000 parts per million by
`
`weight (based on the weight of the polyethylene) so it will be appreciated by those
`
`skilled in the art that some care must be taken to ensure that the nucleating agent is
`
`well dispersed.
`
`It is preferred to add the nucleating agent in finely divided form (less
`
`than 50 microns, especially less than 10 microns) to the polyethylene to facilitate
`
`mixing. A n alternative to a "physical blend" (i.e. a mixture of the nucleating agent and
`
`the resin in solid form) is the use of a "masterbatch" of the nucleator (where the term
`
`"masterbatch" refers to the practice of first melt mixing the additive - the nucleator, in
`
`this case - with a small amount of HDPE resin - then melt mixing the "masterbatch"
`
`with the remaining bulk of the HDPE resin).
`
`It is especially preferred to include a metal stearate (such as zinc or calcium
`
`stearate) in a 1/2 to 2/1 weight ratio with respect to the nucleating agent. While not
`
`wishing to be by theory, it is believed that the stearate may improve the dispersion of
`
`the nucleating agent.
`
`Examples of nucleating agents which may be suitable for use in the present
`
`invention include the cyclic organic structures disclosed in USP 5,981 ,636 (and salts
`
`thereof, such as disodium bicycio [2.2.1] heptene dicarboxylate);
`
`the saturated versions
`
`of the structures disclosed in USP 5,981 ,636 (as disclosed in USP 6,465,551 ; Zhao et
`
`al., to Milliken); zinc glycerolate; the salts of certain cyclic dicarboxylic acids having a
`
`hexahydrophtalic acid structure (or "HHPA" structure) as disclosed in USP 6,559,971
`
`(Dotson et al., to Milliken); and phosphate esters, such as those disclosed in USP
`
`5,342,868 and those sold under the trade names NA-1 1 and NA-21 by Asahi Denka
`
`Kogyo. Preferred barrier nucleating agents are cylic dicarboxylates and the salts
`
`thereof, especially the divalent metal or metalloid salts, (particularly, calcium salts) of
`
`the HHPA structures disclosed in USP 6,559,971 . For clarity, the HHPA structure
`
`generally comprises a ring structure with six carbon atoms
`
`the ring and two
`
`carboxylic acid groups which are substituents on adjacent atoms of the ring structure.
`
`The other four carbon atoms in the ring may be substituted, as disclosed in USP
`
`6,559,971 . A preferred example is 1,2 - cyclohexanedicarboxylic acid, calcium salt
`
`(CAS registry number 491589-22-1).
`
`0005
`
`

`

`C .
`
`LDPE
`
`The core layer of the films of this invention is prepared from a blend of a)
`
`"nucleated HDPE" and b) high pressure, low density polyethylene (or "LDPE").
`
`The relative amounts of nucleated HDPE and LDPE in the core layer are from 5
`
`to 40 weight% LDPE with 95 to 60 weight% nucleated HDPE (especially from 8 to 20
`
`weight% LDPE with 92 to 80 weight% nucleated HDPE).
`The LDPE preferably has a melt index, l2, of from 0.5 to 3 grams per 0 minutes
`(as measured by ASTM D1238 at 190°C using a 2.16 kg weight) and a density of from
`
`0.917 to 0.922 grams per cubic centimeter (g/cc).
`
`D.
`
`Film Structure
`
`A three layer film structure may be described as layers A-B-C, where the internal
`
`layer B (the "core" layer) is sandwiched between two external "skin" layers A and C .
`
`In
`
`many multilayer films, one (or both) of the skin layers is made from a resin which
`
`provides good seal strength and is typically referred to as a sealant layer.
`
`Table 1 illustrates a comparative three layer film structure (which was first
`
`disclosed in CA 2,594,472, Aubee et al.). As shown in the examples, this type of
`
`structure can provide very good curl resistance. It contains nucleated HDPE in both of
`
`the core layer and a skin layer (with a sealant resin forming the other skin layer). The
`
`sealant resin is LDPE (as described in Part C , above).
`
`However, when the skin layer is replaced with other resins- such as linear low
`
`density polyethylene ("LLDPE"); or HDPE that does not contain a nucleating agent,
`
`then some "curl" is often observed.
`
`Five, seven and nine layer film structures are also within the scope of this
`
`invention. As will be appreciated by those skilled in the art, it is known to prepare
`
`barrier films with excellent VWTR performance by using a core layer of nylon and skin
`
`layers made from conventional HDPE (or LLDPE) and conventional sealant resins.
`
`These structures generally require "tie layers" to prevent separation of the nylon core
`
`layer from the extra layers. For some applications, the three layer structures described
`
`above may be used instead of the 5 layer structures with a nylon (polyamide) core.
`
`In preferred 5 layer structures according to the present invention, the (nucleated)
`
`blend of HDPEs in the core layer is in direct contact with layers made from a lower
`
`density polyethylene (e.g. LLDPE) to improve the mechanical and tear properties of the
`
`five layer structure. The two "skin layers" of these structures may be made from
`
`polyethylene, polypropylene, cyclic olefin copolymers - with one of the skin layers most
`
`preferably being made from a sealant resin.
`
`0006
`
`

`

`Seven layer structures allow for further design flexibility.
`
`In a preferred seven
`
`layer structure, one of the layers consist of nylon (polyamide) - or an alternative polar
`
`resin having a desired barrier property - and two tie layers which incorporate the nylon
`
`layer into the structure. Nylon is comparatively expensive and difficult to use. The 7
`
`layer structures of this invention allow less of the nylon to be used (because of the
`
`excellent WVTR performance of the core layer of this invention). Curl behavior is
`
`represented on a qualitative scale from 1 to 5 . MD curl and TD curl refer to the
`
`tendency for the film to curl in the Machine Direction (MD) and Transverse Direction
`
`(TD) respectively. A value of "0" indicates no curl and a value of 5 indicates severe curl.
`
`A summary of different three layer structures that we have tested is shown in Table 2 .
`
`The core layer of the multilayer films is preferably from 40 to 70 weight % of thin
`
`films (having a thickness of less than 2 mils). For all films, it is preferred that the core
`
`layer is at least 0.5 mils thick.
`
`(Comparative) Structure from Aubee et al.; CA 2,594,472
`
`TABLE 1
`
`The term n.HDPE (used in the core layer and skin layer A) identifies an HDPE
`
`containing a nucleating agent.
`
`E .
`
`Other Additives
`
`The polymers used to prepare the films of this invention may also contain other
`
`conventional additives, especially (1) primary antioxidants (such as hindered phenols,
`
`including vitamin E); (2) secondary antioxidants (especially phosphites and
`
`phosphonites); and (3) process aids (especially fluoroelastomer and/or polyethylene
`
`glycol process aid).
`
`F.
`
`Film Extrusion Process
`
`Blown Film Process
`
`The extrusion-blown film process is a well known process for the preparation of
`
`multilayer plastic film. The process employs multiple extruders which heat, melt and
`
`0007
`
`

`

`convey the molten plastics and forces them through multiple annular dies. Typical
`extrusion temperatures are from 330 to 500°F, especially 350 to 460°F.
`
`The polyethylene film is drawn from the die and formed into a tube shape and
`
`eventually passed through a pair of draw or nip rollers.
`
`Internal compressed air is then
`
`introduced from the mandrel causing the tube to increase in diameter forming a
`
`"bubble" of the desired size. Thus, the blown film is stretched in two directions, namely
`
`in the axial direction (by the use of forced air which "blows out" the diameter of the
`
`bubble) and in the lengthwise direction of the bubble (by the action of a winding
`
`element which pulls the bubble through the machinery). External air is also introduced
`
`around the bubble circumference to cool the melt as it exits the die. Film width is varied
`
`by introducing more or less internal air into the bubble thus increasing or decreasing the
`
`bubble size. Film thickness is controlled primarily by increasing or decreasing the
`
`speed of the draw roll or nip roll to control the draw-down rate. Preferred multilayer
`
`films according to this invention have a total thickness of from 1 to 4 mils.
`
`The bubble is then collapsed into two doubled layers of film immediately after
`
`passing through the draw or nip rolls. The cooled film can then be processed further by
`
`cutting or sealing to produce a variety of consumer products. While not wishing to be
`
`bound by theory, it is generally believed by those skilled in the art of manufacturing
`
`blown films that the physical properties of the finished films are influenced by both the
`
`molecular structure of the polyethylene and by the processing conditions. For example,
`
`the processing conditions are thought to influence the degree of molecular orientation
`
`(in both the machine direction and the axial or cross direction).
`
`A balance of "machine direction" ("MD") and "transverse direction" ("TD" - which
`
`is perpendicular to MD) molecular orientation is generally considered most desirable for
`
`key properties associated with the invention (for example, Dart Impact strength,
`
`Machine Direction and Transverse Direction tear properties).
`
`Thus, it is recognized that these stretching forces on the "bubble" can affect the
`
`physical properties of the finished film.
`
`In particular, it is known that the "blow up ratio"
`
`(i.e. the ratio of the diameter of the blown bubble to the diameter of the annular die) can
`
`have a significant effect upon the dart impact strength and tear strength of the finished
`
`film.
`
`Further details are provided in the following examples.
`
`EXAMPLES
`
`Example 1
`
`0008
`
`

`

`The films were made on a three layer coextrusion film line manufactured by
`
`Brampton Engineering. Three layer films having a total thickness of 2 mils were
`
`prepared using a blow up ratio (BUR) of 2/1 .
`
`The "sealant" layer (i.e. the skin layers identified as layer C in Table 2) was
`
`prepared from a conventional high pressure, low density polyethylene homopolymer
`
`having a melt index of about 2 grams/10 minutes unless otherwise indicated. Such low
`
`density homopolymers are widely available items of commerce and typically have a
`
`density of from about 0.91 5 to 0.930 g/cc.
`
`Water Vapor Transmission Rate ("WVTR", expressed as grams of water vapor
`
`transmitted per 00 square inches of film per day at a specified film thickness (mils), or
`
`g/100 in2/day) was measured in accordance with ASTM F1249-90 with a MOCON
`
`permatron developed by Modern Controls Inc. at conditions of 100°F (37.8° C) and
`
`100% relative humidity.
`
`As shown in Table 2 , some curl was observed when the first skin layer was
`
`prepared with LLDPE or HDPE. However, this problem could be mitigated by the
`
`addition of nucleated HDPE to the skin layer (i.e. to form a blend of nucleated and non-
`
`nucleated HDPE or a blend of LLDPE with nucleated HDPE). The use of these blends
`
`in the skin layer was observed to produce films having a small amount of "curl" (and
`
`such films would be satisfactory for many end uses/applications).
`
`Surprisingly, the addition of some LDPE to the core layer was observed to
`
`produce multilayer films with little or no curl (see inventive films 16-22). That is, the use
`
`of a core layer that consisted of a blend of nucleated HDPE with LDPE was observed to
`
`produce "flat" film.
`
`TABLE 2
`
`0009
`
`

`

`WO 2014/005214
`PCT/CA2013/000555
`
`4-C
`35%
`50%
`15%
`0
`|
`oO
`
`
`
`HDPE-A 70% n.HDPE-1|LDPE-A
`
`_ LDPE-2
`n.HDPE-1
`n. HDPE
`
`35%
`50%
`15%
`
`|
`
`|
`
`5
`
`|
`
`4
`
`"6c |
`
`.
`+ 30 LLDPE-A
`
`1 5-c| 15%
`50%
`“|
`35%
`5
`|
`2
`
`
`
`
`
`
`
`
`
`n.HDPE-1
`n.HDPE-1
`LDPE-A
`
`35%
`50% | 15%
`
`5
`
`|
`
`3
`
`|
`
`7c |
`
`
`
`70% HDPE-A + 30%|n.HDPE-1 LDPE-A
`
`LLDPE-A
`
`8-C |
`35%
`50%
`[15% | 35 |.
`1
`
`70% HDPE-A + 30%|70% n.HDPE-1|LDPE-A
`
`LLDPE-A
`
`+ 30% LLDPE-
`
`A
`
`Cc |
`35%
`|
`50%
`15%
`0
`0. |
`
`
`
`HDPE-A 70% n.HDPE-1}LDPE-A
`
`+ 30% LLDPE-
`
`A
`
`40-c|
`35%
`50%
`15%
`o
`|
`o
`
`|
`
`
`
`HDPE-A 85% n.HDPE-1|LDPE-A
`
`+ 15% LLDPE-
`
`A
`
`| 11-C
`35%
`50%
`15%
`5 |
`1
`
`HDPE-A
`n.HDPE-1
`LDPE-A
`
`12-C
`35%
`50%
`|
`15%
`0
`0
`
`n. HDPE-A
`n.HDPE-1
`LDPE-A
`
`13-C
`35%
`50%
`15%
`5
`[|
`4
`
`
`
`HDPE-A 70% n.HDPE-1|LDPE-A
`
`+ 30% 19C
`
`
`)14-c | 35% 50% 15% 0 | 0
`
`
`
`
`
`69% 19C +30%|70% n.HDPE-1|LDPE-A
`
`15-C |
`
`n.HDPE-1
`35%
`
`+ 30% HDPE-A
`50%
`
`[15%
`
`0. |
`
`0
`
`
`
`70% HDPE-A + 30%|n.HDPE-1 LDPE-A
`
`0010
`
`-C
`
`-C
`
`-C
`
`-C
`
`-C
`
`-C
`
`35%
`
`HDPE-A
`
`50%
`
`15%
`
`70% n.HDPE-1
`
`LDPE-A
`
`15%
`
`. LDPE-2
`
`35%
`
`n.HDPE-1
`
`35%
`
`+ 30 LLDPE-A
`
`50%
`
`35%
`
`n.HDPE-1
`
`n.HDPE
`
`50%
`
`15%
`
`n.HDPE-1
`
`LDPE-A
`
`50%
`
`15%
`
`0
`
`5
`
`5
`
`5
`
`70% HDPE-A + 30%
`
`n.HDPE-1
`
`LDPE-A
`
`LLDPE-A
`
`35%
`
`50%
`
`15%
`
`3.5
`
`70% HDPE-A + 30% 70% n.HDPE-1
`
`LDPE-A
`
`LLDPE-A
`
`+ 30% LLDPE-
`
`35%
`
`HDPE-A
`
`A
`
`50%
`
`15%
`
`0
`
`70% n.HDPE-1
`
`LDPE-A
`
`+ 30% LLDPE-
`
`A
`
`0
`
`2
`
`1
`
`3
`
`1
`
`0
`
`-C
`
`-C
`
`-C
`
`-C
`
`-C
`
`-C
`
`35%
`
`HDPE-A
`
`50%
`
`15%
`
`85% n.HDPE-1
`
`LDPE-A
`
`+ 15% LLDPE-
`
`A
`
`50%
`
`15%
`
`n.HDPE-1
`
`LDPE-A
`
`50%
`
`15%
`
`35%
`
`HDPE-A
`
`35%
`
`n . HDPE-A
`
`n.HDPE-1
`
`LDPE-A
`
`35%
`
`HDPE-A
`
`50%
`
`15%
`
`70% n.HDPE-1
`
`LDPE-A
`
`+ 30% 19C
`
`35%
`
`50%
`
`15%
`
`69% 19C + 30%
`
`70% n.HDPE-1
`
`LDPE-A
`
`n.HDPE-1
`
`+ 30% HDPE-A
`
`35%
`
`50%
`
`15%
`
`70% HDPE-A + 30%
`
`n.HDPE-1
`
`LDPE-A
`
`0
`
`5
`
`0
`
`5
`
`0
`
`0
`
`0
`
`1
`
`0
`
`1
`
`0
`
`0
`
`0010
`
`

`

`PCT/CA2013/000555
`
`n.HDPE-1
`dS
`
`
`16 -
`35%
`50%
`15%
`0
`|
`0
`
`
`
`HDPE-A 70% n.HDPE-1|LDPE-A
`
`+ 30% LDPE-A
`
`17
`35%
`50%
`15%
`1
`|
`1
`
`70% HDPE-A + 30%|70% n.HDPE-1|LDPE-A
`
`LDPE-A
`+ 30% LDPE-A
`
`18
`35%
`50%
`15%
`5
`|
`38
`
`
`
`70% HDPE-A + 30%|n.HDPE-1 LDPE-A
`
`LDPE-A
`
`35%
`
`50%
`
`15%
`
`5
`
`|
`
`2
`
`19
`
`HDPE-A
`n.HDPE-1
`LDPE-A
`
`20-C
`35%
`50%
`15%
`4
`| t
`
`
`
`HDPE-A 95% n.HDPE-1|LDPE-A
`
`+ 5% LDPE-A
`
`
`22
`
`35%
`
`50%
`
`15%
`
`0
`
`0
`
`
`
`HDPE-A 70% n.HDPE-1|LDPE-A
`
`
`
`
` WO 2014/005214
`
`
`
`
`+ 30% LDPE-A
`
`50%
`
`15%
`
`0.5
`
`0.5
`
`23-0 |
`
`35%
`
`n.HDPE-1 + 1%
`
`n.HDPE-1
`
`LDPE-A
`
`1150
`
`24-6 |
`35%
`50%
`15%
`5
`3
`
`HDPE-A
`n.HDPE-1
`LDPE-A
`
`
`25-C
`
`15%
`
`50%
`
`35%
`
`5
`
`0.5
`
`LDPE-2
`n.HDPE-1
`HDPE-A
`
`26-C |
`15%
`50%
`35%
`0
`|
`0
`
`
`
`LDPE-2 70% n.HDPE-1|30%
`
`+ 30% HDPE-A)n.HDPE-
`
`27-C|
`
`35%
`
`50%
`
`15%
`
`5 | 2
`
`HDPE-A
`
`n.HDPE-1
`
`LDPE-A
`
`1, 70%
`
`HDPE-A
`
`10
`
`0011
`
`n.HDPE-1
`
`-
`
`6 -
`
`7
`
`8
`
`9
`
`-C
`
`35%
`
`HDPE-A
`
`50%
`
`15%
`
`70% n.HDPE-1
`
`LDPE-A
`
`+ 30% LDPE-A
`
`35%
`
`50%
`
`15%
`
`70% HDPE-A + 30% 70% n.HDPE-1
`
`LDPE-A
`
`LDPE-A
`
`35%
`
`+ 30% LDPE-A
`
`50%
`
`15%
`
`70% HDPE-A + 30%
`
`n.HDPE-1
`
`LDPE-A
`
`LDPE-A
`
`35%
`
`HDPE-A
`
`35%
`
`HDPE-A
`
`50%
`
`15%
`
`n.HDPE-1
`
`LDPE-A
`
`50%
`
`15%
`
`95% n.HDPE-1
`
`LDPE-A
`
`+ 5% LDPE-A
`
`50%
`
`15%
`
`0
`
`1
`
`5
`
`5
`
`4
`
`0
`
`0
`
`1
`
`3
`
`2
`
`1
`
`0
`
`2
`
`-C
`
`-C
`
`-C
`
`-C
`
`-C
`
`35%
`
`HDPE-A
`
`70% n.HDPE-1
`
`LDPE-A
`
`+ 30% LDPE-A
`
`35%
`
`50%
`
`15%
`
`0.5
`
`0.5
`
`n.HDPE-1 + 1%
`
`n.HDPE-1
`
`LDPE-A
`
`1150
`
`35%
`
`HDPE-A
`
`15%
`
`LDPE-2
`
`15%
`
`LDPE-2
`
`35%
`
`HDPE-A
`
`3
`
`0.5
`
`0
`
`50%
`
`15%
`
`n.HDPE-1
`
`LDPE-A
`
`50%
`
`35%
`
`n.HDPE-1
`
`HDPE-A
`
`50%
`
`70% n.HDPE-1
`
`35%
`
`30%
`
`+ 30% HDPE-A n.HDPE-
`
`5
`
`5
`
`0
`
`1, 70%
`
`HDPE-A
`
`50%
`
`15%
`
`5
`
`2
`
`n.HDPE-1
`
`LDPE-A
`
`0011
`
`

`

`28-C
`
`29-C
`
`35%
`
`HDPE-C
`
`35%
`
`HDPE-A
`
`50%
`
`15%
`
`n.HDPE-1
`
`LDPE-A
`
`50%
`
`15%
`
`n.HDPE-1
`
`LDPE-A
`
`5
`
`5
`
`1
`
`2
`
`Brief description of the polyethylene resins used to prepare the films of Table 2 are
`
`provided below:
`LLDPE - A : an ethylene/octene copolymer having a melt index (l2) of 0.65 g/ 0 minutes
`and a density of 0.916 g/cc.
`HDPE - A : an ethylene homopolymer having a melt index (l2) of 0.95 g/1 0 minutes and
`a density of 0.958 g/cc.
`
`n.HDPE-1 : a nucleated HDPE having a density of 1.2 g/10 minutes and a density of
`
`0.966 g/cc.
`
`n.HDPE: homopolymer HDPE-A (above) + nucleating agent
`LDPE-A: a high pressure, low density ethylene homopolymer having a melt index (l2) of
`0.75 g/1 0 minutes and a density of 0.919 g/cc.
`LDPE-2: a high pressure, low density ethylene homopolymer having a melt index (l2) of
`2.2 g/10 minutes and a density of 0.923 g/cc.
`HDPE-B: an ethylene homopolymer having a melt index (l2) of 0.85 g/10 minutes and a
`density of 0.958 g/cc.
`HDPE-C: an ethylene homopolymer having a melt index (l2) of 2.8 g/10 minutes and a
`density of 0.958 g/cc.
`
`-C: comparative example
`
`A fluoroelastomer process (of the type that is conventionally used to reduce melt
`
`fracture) was added to skin layer A of the following films: 6 , 14, 15 , 17, 18, and 28.
`INDUSTRIAL APPLICABILITY
`
`The multilayer films of this invention are suitable for the preparation of a wide
`
`variety of packages. They are especially suitable for the preparation of packages for
`
`"dry" foods such as crackers and breakfast cereals.
`
`0012
`
`

`

`CLAIMS
`" A barrier film comprising a core layer and two skin layers, wherein said core
`
`.
`
`layer consists essentially of a blend of:
`
`a)
`
`b)
`
`from 92 to 60 weight% of a nucleated high density polyethylene resin; and
`
`. from 8 to 40 weight% of high pressure, low density polyethylene.
`
`The barrier film of Claim 1 wherein said high pressure, low density polyethylene
`2 .
`has a melt index, l2, of from 0.5 to 3 grams per 10 minutes and a density of from 0.917
`to 0.922 g/cc.
`
`The barrier resin of Claim 1 wherein said nucleated high density polyethylene
`3 .
`has a melt index, l2, of from 0.3 to 20 grams/10 minutes.
`The barrier resin of Claim 1 wherein at least one of said skin layers comprises a
`4 .
`
`sealant resin selected from the group consisting of EVA, ionomer and polybutylene.
`
`5 .
`
`6 .
`
`7 .
`
`8 .
`
`The barrier film of Claim 1 which consists of 5 layers.
`
`The barrier film of Claim 1 which consists of 7 layers.
`
`The barrier film of Claim 1 which consists of 9 layers.
`
`The barrier film of Claim 1 wherein said nucleated HDPE contains a nucleating
`
`agent that is a salt of a dicarboxylic acid.
`
`9 .
`
`The barrier film of Claim 8 wherein said dicarboxylic acid is a cyclic dicarboxylic
`
`acid having a hexahydrophtalic structure.
`
`0013
`
`

`

`INTERNATIONAL SEARCH REPORT
`
`International application No.
`PCT/CA2013/000555
`
`A .
`
`CLASSIFICATION OF SUBJECT MATTER
`IPC: B32B 27/08 (2006.01) . B32B 27/32 (2006.01)
`According to International Patent Classification (IPC) or to both national classification and IPC
`
`B . FIELDS SEARCHED
`Minimum documentation seaixhed (classification system followed by classification symbols)
`B32B (2006.01). B32B 27/08 (2006.01). B32B 27/32 (2006.01)
`
`Documentation searched other than minimum documentation to the extent that such documents are included in the fields searched
`
`Electronic database(s) consulted during the international search (name of database(s) and, where practicable, search terms used)
`TotalPatent, Canadian Patent Database (polyethylene, nucleat*, density, high, low, barrier, HDPE, LDPE)
`
`C . DOCUMENTS CONSIDERED TO BE RELEVANT
`
`Category'
`
`Citation of document, with indication, where appropriate, of the relevant passages
`
`Relevant to claim No.
`
`A
`
`A
`
`WO 201 1/154840 (Haley) 15 December 201 1 ( 15-12-201 1)
`* abstract; claims *
`
`CA 2 594 472 (Aubee et aL) 23 January 2009 (23-01-2009)
`* cited by applicant *
`* abstract; claims *
`
`1-9
`
`1-9
`
`Further documents are listed in the continuation of Box C .
`
`Special categories of cited documents :
`
`document defining the general state of the art which is not considered
`to be of particular relevance
`
`earlier application or patent but published on or after the international
`filing date
`
`document which may t r n doubts on priority clami(s) or which is
`cited to establish the publication date of another citation or other
`special reason (as specified)
`
`document referring to an oral disclosure, use, exhibition or other means
`
`document published prior to the international filing date but later than
`the priority date claimed
`
`[X ]
`Ύ"
`
`X "
`
`"Y
`
`See patent family annex.
`
`later document published after the international filing date or priority
`date and not m conflict with the application but citecTto understand
`the principle or theorv underlying the invention
`
`document of particular relevance the claimed invention cannot be
`considered novel or cannot be considered to involve an inventive
`step when the document is taken alone
`
`document of particular relevance the claimed invention cannot be
`considered to involve an inventive step when the document is
`combined rath one or more other such documents such combination
`being obvious to a person skilled m the art
`
`document member of the same patent family
`
`Date of the actual completion of the international search
`
`Date of mailing of the international search report
`
`25 July 20 13 (25-07-2013)
`
`Name and mailing address of the ISA/CA
`Canadian Intellectual Property Office
`Place du Portage I, C I 14 - 1st Floor, Box PCT
`50 Victoria Street
`Gatineau, Quebec K1A 0C9
`Facsimile No.: 001-819-953-2476
`
`Form PCT ISA 2 10 (second sheet ) (July 2009)
`
`05 September 2013 (05-09-2013)
`
`Authorized officer
`
`Marie Quinn (8 19) 934-1346
`
`Page 2 of 3
`
`0014
`
`

`

`INTERNATIONAL SEARCH REPORT
`Information o patent family members
`
`International application No.
`PCT/CA2013/000555
`
`Patent Document
`Cited in Search Report
`
`WO201 1154840A1
`
`Publication
`Date
`
`Patent Family
`Member(s)
`
`Publication
`Date
`
`15 December 201 1 (15- 12-201 1) EP2580055A1
`US201 1300391A1
`
`17 April 2013 (17-04-2013)
`08 December 201 1 (08-12-201 1)
`
`CA2594472A1
`
`23 January 2009 (23-01-2009)
`
`AU2008280776A1
`CN101868348A
`EP2170603A1
`EP2170603A4
`NZ582494A
`US2009029182A1
`WO2009012565A1
`
`29 January 2009 (29-01-2009)
`20 October 2010 (20-10-2010)
`07 April 2010 (07-04-2010)
`15 May 2013 (15-05-2013)
`29 July 201 1 (29-07-201 1)
`29 January 2009 (29-01-2009)
`29 January 2009 (29-01-2009)
`
`Form PCT/ISA/210 (patent family annex ) (July 2009)
`
`Page 3 of 3
`
`0015
`
`