GB2290500A - Thermoplastic composite film intended for packaging - Google Patents

Thermoplastic composite film intended for packaging Download PDF

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Publication number
GB2290500A
GB2290500A GB9511886A GB9511886A GB2290500A GB 2290500 A GB2290500 A GB 2290500A GB 9511886 A GB9511886 A GB 9511886A GB 9511886 A GB9511886 A GB 9511886A GB 2290500 A GB2290500 A GB 2290500A
Authority
GB
United Kingdom
Prior art keywords
film according
substrate
tear strength
ionic polymer
film
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
GB9511886A
Other versions
GB9511886D0 (en
Inventor
Yves Greuet
Alain Vialleton
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
FAYARD AND RAVEL
Original Assignee
FAYARD AND RAVEL
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by FAYARD AND RAVEL filed Critical FAYARD AND RAVEL
Publication of GB9511886D0 publication Critical patent/GB9511886D0/en
Publication of GB2290500A publication Critical patent/GB2290500A/en
Withdrawn legal-status Critical Current

Links

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B27/00—Layered products comprising a layer of synthetic resin
    • B32B27/06—Layered products comprising a layer of synthetic resin as the main or only constituent of a layer, which is next to another layer of the same or of a different material
    • B32B27/08—Layered products comprising a layer of synthetic resin as the main or only constituent of a layer, which is next to another layer of the same or of a different material of synthetic resin
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B27/00—Layered products comprising a layer of synthetic resin
    • B32B27/32—Layered products comprising a layer of synthetic resin comprising polyolefins
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B27/00—Layered products comprising a layer of synthetic resin
    • B32B27/18—Layered products comprising a layer of synthetic resin characterised by the use of special additives
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
    • C08J5/00—Manufacture of articles or shaped materials containing macromolecular substances
    • C08J5/18—Manufacture of films or sheets
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B2307/00—Properties of the layers or laminate
    • B32B2307/50—Properties of the layers or laminate having particular mechanical properties
    • B32B2307/582—Tearability
    • B32B2307/5825—Tear resistant
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B2307/00—Properties of the layers or laminate
    • B32B2307/70—Other properties
    • B32B2307/732—Dimensional properties
    • B32B2307/734—Dimensional stability
    • B32B2307/736—Shrinkable
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B2439/00—Containers; Receptacles
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B2553/00—Packaging equipment or accessories not otherwise provided for
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
    • C08J2323/00—Characterised by the use of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Derivatives of such polymers
    • C08J2323/02—Characterised by the use of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Derivatives of such polymers not modified by chemical after treatment
    • C08J2323/04—Homopolymers or copolymers of ethene
    • C08J2323/06—Polyethene

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  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Manufacturing & Machinery (AREA)
  • Materials Engineering (AREA)
  • Health & Medical Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Medicinal Chemistry (AREA)
  • Polymers & Plastics (AREA)
  • Organic Chemistry (AREA)
  • Laminated Bodies (AREA)
  • Manufacture Of Macromolecular Shaped Articles (AREA)

Description

2290500 R:1 RMOPLASTIC COMPOSITE FILM INTENDED FOR PACKAGING The present
invention relates to a thermoplastic composite f ilm intended for packaging, which can, in particular, be welded to itself. In addition, the thermoplastic f ilms according to the invention may be shrinkable, that is to say capable in succession of sof tening under the ef f ect of heat, in order to remove the internal stresses in them, and of contracting or shrinking under the effect of rapid cooling.
More precisely, the invention concerns composite films, which are easy to tear, including after shrinking, the substrate of which combines, either in the form of a single layer of extruded resin or in the f orm of at least two layers, bonded to each other and obtained by co- is extrusion, for example:
an ionic polymer obtained from at least one olefinic monomer, the olefinic monomer or monomers being the major components in molar proportion, and from an unsaturated carboxylic acid, the carboxylic acid groups of which polymer are neutralized by metal ions; and a polyolefin.
The subject of the present invention is a film such as defined above, exhibiting tearability in virtually all directions within it, these directions being considered with reference to the longitudinal extrusion direction of the composite film, as well as a packaging comprising such a film.
In accordance with the present invention, it has been discovered that a composite film formed by resins such as those defined above could be easily tearable, without any preferred direction with respect to the longitudinal extrusion direction, on condition that the following mechanical characteristics, which may be checked by routine tests according to the Elmendorf measurement method (French Standard NFT54-141), are met:
the longitudinal tear strength (D,), expressed in cN/gm, in the extrusion direction, is at most equal to 0.8 and the transverse tear strength (DJ, perpendicular to the longitudinal direction, is at most equal to 2.0 the ratio Dt in less than 4; Dz in order to obtain, in particular, an oblique tear strength (D.), in a direction at 450 with respect to the longitudinal and transverse directions, at most equal to 2.5.
Preferably, the ratio between the oblique tear strength (D.) and the transverse tear strength (D,) is less than 1.5.
The substrate of the film according to the invention may comprise from 30 up to 80 % by weight, and preferably from 50 to 70 % by weight, of the ionic copolymer.
As regards the choice of the ionic polymer, this may be a copolymer of an olefin of general formula R-CE=CE2F in which R is a hydrogen atom or a lower alkyl radical, and of an ethylenically unsaturated a- or Pcarboxylic acid also having a short chain, comprising from 0. 2 to 2 0 %, preferably from 1 to 5 % (molar percentage), of carboxylic acid groups ionized by neutralization with metal ions distributed along the polymer. 25 Preferably, the ionic polymer is a copolymer of ethylene and methaerylic acid. The ionic polymer may also be a terpolymer of an olefin, a monoethylenic unsaturated compound different from the olefin, and methaerylic acid. 30 The valences of the metal ion will depend on the carboxylic acid used. Preferably, ions will be used having a valency between 1, 2 or 3. In general, the ions chosen may be complexed or uncomplexed metal ions. The ionic polymers most often used are copolymers of ethylene and monocarboxylic or dicarboxylic acid, in which the metal ions belong to Groups II, III, IV-A and VIII of the Periodic Table of the Elements, if they are in complexed form, or else to Group 1, if they are not.
As regards polyolefin, this term denotes, in the present description, homopolymers of ok-olefins or copolymers of these same olefins with one or more monomers.
For example, the 0(-olef in homopolymer is obtained from an olefinic monomer identical to that of the ionic polymer. The copolymers of C(olefins may also consist of c-olefin copolymers in combination with at least one other monoethylenically unsaturated monomer, such as an aliphatic or aromatic monomer, among which may be mentioned, by way of example, vinyl acetate, styrene and methacrylic derivatives.
Advantageously, the polyolefin is a low-density polyethylene, especially obtained by radical polymerization.
The substrate according to the invention may alsoinclude additives improving its behaviour. For example, such an additive is advantageously an antistatic, slip and antiblocking agent, possibly diluted in a polyolefinic base.
The form of the substrate may vary depending on the applications envisaged for the films of the invention. in particular, the substrate may consist of a single layer or of at least two layers, namely of the ionic copolymer and the polyolefin respectively.
Preferably, the substrate has a thickness of between 20 and 400-AP.
The invention will be better understood with the help of the following examples given solely by way of illustration. EXAMPLES COMPOSITION 1 (prior art):
Monolayer standard film having a thickness of 60,um, extruded, consisting of a mixture formed by 70 % by weight of low-density polyethylene, obtained by radical polymerization, and by 30 k by weight of a linear lowdensity polyolef in, obtained by polymerization of 4methyl-l-pentene. COMPOSITION 2:
Three-layer film having a thickness of 601am, coextruded, comprising a central layer of an ionic copolymer of ethylene (major component in molar proportion) and methacrylic acid - reference EXP 5059 of the BP Chemicals company - and two outer layers of a lowdensity polyethylene obtained by radical route reference EXP 1003 of the BP Chemicals company; the central layer represents 60 % by weight of the substrate of the film and each of the outer layers 20 W by weight of the same substrate. COMPOSITION 3:
Monolayer film, extruded having a thickness of 60,Um, comprising the same components as above, in the same proportions, but obtained by extruding the mixture as one and the same layer.
Table 1 represents the results obtained from tests of the tearability of each film according to the French Standard NFT 54-141 (Elmendorf method) It may clearly be seen that Compositions 2 and 3 (three-layer and monolayer) of the invention possess tear strengths markedly lower than those of a film according to the prior art (Composition 1), and this is so in all the directions indicated.
The major advantage afforded by the films of the invention is that the low tear strength in the directions indicated allows these films to be readily used in the f ield of tearable packaging.
The reason for this is that the placing of the tear initiators, which are normally incorporated into or laid on such films so as to make it easier to open the packaging, is no longer limited to just the extrusion and transverse directions, thereby removing the known constraints in films of the prior art.
Consequently, it now becomes possible to manufacture packaging from heatshrinkable film according to the invention having possibilities of opening which hitherto were difficult, nay impossible, to achieve.
Table 1 composite film Film according Three-layer Monolayer Tear strength to the prior film, of Com- film of art position (2) Composition of composition according to (3) according (1) the invention to the invention Longitudinal 3,35 0.42 0.6 strength D, in CNIgm.
Transverse 9.73 1.17 1.5 strength D, in CNIPM Oblique strength D. In cul=, at 450C [sic] with respect to the 4.07 2.25 1.7 longitudinal and is transverse directions according to the Elmendorf method (French Standard NFT 54-141)

Claims (11)

  1. Thermoplastic composite film, especially a shrinkable one, obtained by extrusion, the substrate of which comprises:
    an ionic polymer obtained from at least one olefinic monomer, the olefinic monomer or monomers being the major components in molar proportion, and from an unsaturated carboxylic acid, the carboxylic acid groups of which polymer are neutralized by metal ions; and a polyolefin characterized in that, expressed in cN/gm according to the Elmendorf method, the longitudinal tear strength (DL) 1 in the extrusion direction, in at most equal to 0. 8 and the transverse tear strength (D.), perpendicular to the longitudinal direction, is at most equal to 2.0, satisfying a Dt/DL ratio less than 4, in order to obtain an oblique tear strength (D.), in a direction at 45 with respect to the longitudinal and transverse directions, at most equal to 2.5.
  2. 2. Film according to Claim 1, characterized in that the ratio between the oblique tear strength (D.) and the transverse tear strength (Dt) is less than 1.5.
  3. 3. Film according to Claim 1, characterized in that the substrate furthermore includes an antistatic, slip and antiblocking agent, possibly diluted in a poly olefinic base.
  4. 4. Film according to Claim 1, characterized in that the substrate comprises from 30 to 80 % by weight, and preferably from 50 to 70 % by weight, of the ionic copolymer.
  5. 5. Film according to Claim 1, characterized in that the ionic polymer is a copolymer of ethylene and methacrylic acid.
  6. 6. Film according to Claim 1, characterized in that the ionic polymer is a terpolymer of an olefin, a monoethylenic unsaturated compound and methacrylic acid.
  7. 7. Film according to Claim 1, characterized in that - a - the polyolef in is a low-density polyethylene, especially obtained by radical polymerization.
  8. 8. Film according to Claim 1, characterized in that the substrate is formed by a single layer.
  9. 9. Film according to Claim 1, characterized in that the substrate comprises at least two layers, namely of the ionic polymer and the polyolefin respectively.
  10. 10. Film according to Claim 1, characterized in that the substrate has a thickness of between 20 gm and 400 m.
  11. 11. Packaging comprising a film according to any one of Claims 1 to 10.
    11
GB9511886A 1994-06-13 1995-06-12 Thermoplastic composite film intended for packaging Withdrawn GB2290500A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
FR9407406A FR2721007B1 (en) 1994-06-13 1994-06-13 Thermoplastic composite film, intended for packaging.

Publications (2)

Publication Number Publication Date
GB9511886D0 GB9511886D0 (en) 1995-08-09
GB2290500A true GB2290500A (en) 1996-01-03

Family

ID=9464310

Family Applications (1)

Application Number Title Priority Date Filing Date
GB9511886A Withdrawn GB2290500A (en) 1994-06-13 1995-06-12 Thermoplastic composite film intended for packaging

Country Status (4)

Country Link
BE (1) BE1009799A3 (en)
DE (1) DE19521244A1 (en)
FR (1) FR2721007B1 (en)
GB (1) GB2290500A (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1999043498A1 (en) * 1998-02-26 1999-09-02 E.I. Du Pont De Nemours And Company Thermoplastic film for packaging
US6572979B1 (en) 1998-02-26 2003-06-03 E. I. Du Pont De Nemours And Company Thermoplastic film for packaging
WO2017056542A1 (en) * 2015-09-29 2017-04-06 積水フィルム株式会社 Multilayered heat-shrinkable film

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2008102384A1 (en) * 2007-02-20 2008-08-28 Metalpack Srl Film and method to produce said film

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3552638A (en) * 1968-08-14 1971-01-05 Nat Distillers Chem Corp Peel-open thermoplastic package for sterilized articles
GB1592425A (en) * 1978-04-04 1981-07-08 Tower Products Polymer film having linear tear properties
EP0136059A2 (en) * 1983-08-22 1985-04-03 E.I. Du Pont De Nemours And Company Blends of ionomer with propylene copolymer
EP0192131B1 (en) * 1985-02-09 1991-03-13 W.R. Grace & Co.-Conn. An easy to open package and a method of making same
EP0537080A1 (en) * 1991-10-11 1993-04-14 Sodap Shrinkable thermoplastic film for use in packaging

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2665426B2 (en) * 1992-02-25 1997-10-22 出光石油化学株式会社 Easy tearing film and method for producing the same

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3552638A (en) * 1968-08-14 1971-01-05 Nat Distillers Chem Corp Peel-open thermoplastic package for sterilized articles
GB1592425A (en) * 1978-04-04 1981-07-08 Tower Products Polymer film having linear tear properties
EP0136059A2 (en) * 1983-08-22 1985-04-03 E.I. Du Pont De Nemours And Company Blends of ionomer with propylene copolymer
EP0192131B1 (en) * 1985-02-09 1991-03-13 W.R. Grace & Co.-Conn. An easy to open package and a method of making same
EP0537080A1 (en) * 1991-10-11 1993-04-14 Sodap Shrinkable thermoplastic film for use in packaging

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1999043498A1 (en) * 1998-02-26 1999-09-02 E.I. Du Pont De Nemours And Company Thermoplastic film for packaging
EP0940251A1 (en) * 1998-02-26 1999-09-08 Du Pont De Nemours International S.A. Thermoplastic film for packaging
EP1060078A4 (en) * 1998-02-26 2001-05-16 Du Pont Thermoplastic film for packaging
US6572979B1 (en) 1998-02-26 2003-06-03 E. I. Du Pont De Nemours And Company Thermoplastic film for packaging
JP2004517751A (en) * 1998-02-26 2004-06-17 イー・アイ・デュポン・ドウ・ヌムール・アンド・カンパニー Thermoplastic film for packaging
JP4790906B2 (en) * 1998-02-26 2011-10-12 イー・アイ・デュポン・ドウ・ヌムール・アンド・カンパニー Thermoplastic film for packaging
WO2017056542A1 (en) * 2015-09-29 2017-04-06 積水フィルム株式会社 Multilayered heat-shrinkable film

Also Published As

Publication number Publication date
FR2721007A1 (en) 1995-12-15
FR2721007B1 (en) 1996-07-19
DE19521244A1 (en) 1995-12-14
GB9511886D0 (en) 1995-08-09
BE1009799A3 (en) 1997-08-05

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WAP Application withdrawn, taken to be withdrawn or refused ** after publication under section 16(1)