JPS6067150A - Lap for food of laminated film and pouch for said food - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a one-soft boiling one-soiling laminate, r. - Tofilm Od
Lettle made from Yohiko's film!・Meal a6 1t
4/ξRegarding packaging such as home.

There is packaging for retorts, etc. IIσ) Packaging σ) Lr;
1146 ma, , +- , - +I-. w-L-b
puk”JW fi 21; &, tTs Ljb ;M
l l/r 'AI' W- Is I'J Requires construction of a good barrier. In addition, some food packaging requires that a minimum amount of oxygen or air be transferred to the contents. Cheese is one food product that should be packaged to exclude oxygen.

Oriented polyacrylonitrile (PAN) films have penetrating oxygen barrier properties. Its moisture barrier properties (1), however, are undesirable for some packaging purposes. Furthermore, it does not have sealing properties itself. Both drawbacks make it difficult to PAN a layer of thermoplastic material with good moisture barrier properties. This can be overcome by applying it to one side of the PAN.
It is desirable to bond the film to itself. Therefore, it is necessary to consider an adhesive or bonding system between the two or one layers of PAN and the thermoplastic moisture barrier film. By providing an effective adhesive bond between such films, this result will satisfy the 'do requirements' seen in the food packaging industry. In recent years, the food packaging industry has focused on the idea of pouch-packaged foods, which do not require refrigeration for preservation and therefore expensive and energy-intensive refrigeration transport and storage equipment, among other advantages. He has shown great interest. Certain older materials are toxicologically safe and possess a variety of properties sufficient to withstand the rigors of sterilization and subsequent heating, such as microwave heating, and provide adequate protection of the contents during storage. Many efforts have been made to develop flexible food pouches using

According to U.S. Pat. No. 6,453,173, a polyolefin-polyacrylonitrile laminate that can be used in the construction of food containers is said to have excellent heat seal strength and permeable barrier properties to gas transmission. and a polyacrylonitrile surface and adhere them together with an adhesive.

Treatment with a gaseous mixture of boron trifluoride as described in British Patent No. 834,196; US Pat. No. 2,632;
The 11 side or both sides can be pretreated by a bonding method such as flame treatment or corona discharge treatment as described in No. 921. U.S. Patent No. 2,
200.429 is an adhesive used in the manufacture of laminates.

Interlayer adhesion in boiling water is not expected to be strong since the intended manufacturing conditions and adhesives do not favor the formation of primary valence bonds. There have also been ways to plate the PAN film to use a metal layer as an effective surface for adhesion to the water vapor barrier film.

The purpose of ``Duds'' is to provide a polyacrylonitrile film laminate or extrusion phase consisting of two or more PAN layers bonded to each other using a unique and effective bonding system.

It is an object of the present invention to provide a polyacrylonitrile film laminate or composite consisting of PAN and a thermoplastic moisture barrier layer bonded to each other using a unique and effective bonding system.

A further object is to provide a food or product pouch or tube made from one of the above laminates.

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It is an object of the present invention to provide a method for improving fl coupling strength.

In accordance with the present invention, there is provided a flexible film laminate suitable for product packaging and certain food product uses, comprising: (a) ethylene oxide and propylene oxide containing 1 to 10 aliphatic carbon atoms; A liquid heterized compound prepared by reacting a monohydric alcohol with an active hydrogen compound initiator having a
) a stretched polyacrylonitrile film containing an ethylene oxide-propylene oxide copolymer in a fixed proportion; (b) an adhesive layer in contact with the polyacrylonitrile film, the adhesive layer having a (++ M toning ratio); 1:6 to 6:1 styrene-butadiene block co-M1 combination containing mono-11 units, and (2+30 to 40 parts of 1,6-pentadiene-
A random ternary M↓ combination consisting of 30 to 40 M parts of monocyclic terpene and 25 to 351 (1', a second oriented polyacrylonitrile film comprising a block copolymer of 1 to 6 parts relative to the original polymer, and <c) comprising the heterogeneous glaze copolymer in contact with the adhesive layer; Consisting of either one of heat-sealable polyolefins.

A method for bonding two or more polyacrylonitrile films or one polyacrylonitrile film and a heat-sealable polyolefin film to each other by VC adhesive, the method comprising: bonding ethylene oxide and propylene oxide to at least one polyacrylonitrile film having from 1 to 10 carbon atoms; A liquid heterogeneous ethylene oxide-propylene oxide copolymer prepared by reacting a monohydric alcohol with an active hydrogen compound initiator is added to a polyacrylonitrile film at an adhesion-promoting rate, and ( 11L styrene-butadiene floc copolymer with monomer parts in a volume ratio of 1:6 or 1:1;
and (a random terpolymer consisting of 2+30 to 40 parts of 1°3-R-ntadiene, 30 to 40 parts of monocyclic terpene, and 25 to 3 parts of alpha-methylstyrene). Pressure is applied to the surface of the film having an intermediate layer of the composition, wherein the combination is primarily from 1 to 11 parts of terpolymer to 1 to 51 parts of block copolymer or method.

The polyacrylonitrile film of the present invention is composed of a high nitrile (=j+l) incorporation having at least 80% acrylonitrile repeating units.The flat PAN film can be solution cast according to the method of U.S. Pat. No. 4,066,731. Where the acrylonitrile homopolymer or interpolymer is cast from a sheeting die onto a rotating 1.5 ram and aggregated as a self-supporting film, from which the organic solvent in the film, such as dimethyl sulfoxide, is displaced by a water bath. Aquagel films typically containing 40 to 60% water either fully bound in the molecular interstitial spaces or dispersed in an oriented polymer matrix can be obtained by extrusion and water agglomeration of tubular PAN films to yield 75 i The unstretched film can then be slit and fed to processing and stretching equipment as a flat strip.Aqueous PAN films may also be made by melt extruding high temperature polymer hydrates in known manner.

A preferred PAN feedstock is a 41 polymer material containing sufficient water to stretch at one low temperature. at least 5% H20
Acrylonitrile polymers containing 40 to 60% H20, preferably aquagel, are excellent film substrates for use in the present invention. The method is particularly useful for processing PAN homo Hr +)mers such as DuPont Type A resins. Homo-11 serimer PAN, copolymers and interpolymers with monohydrophilic ethylenically unsaturated monomers such as acrylic acids and esters may be adapted to the novel method. Representative high-density IJ phosphorimers are disclosed in U.S. Patent Nos. 2,585,444 and 6,876,50
No. 8, No. 5.896.204, No. 3,984.6
No. 01 and No. 4,056,442, which documents are hereby incorporated by reference.

Inclusion in polyacrylonitrile films as an adhesion promoter. These moon phases are water-soluble or water-loving and have an average molecular weight of 500 to 5000, and 85 to 5
20. It has a Saybolt viscosity at 100'F of C1 seconds. The preferred average molecular weight is 800 to 460 D and the preferred Saybolt viscosity at ID O'P is 160 to 5100 seconds.

q! jlK - preferred average molecular weight is 800 to 200
It is 0. The polyether is present in the film in plasticizing and adhesion promoting proportions. This amount should be at least 1% of the PAN polymer. Furthermore, specifically - the polyether is present in an amount of 5 to 20% by weight of the PAN polymer.

The method for forming a PAN film with this liquid or polyether includes the following steps: (a) Suspending a predetermined concentration of said liquid thieryether in an aqueous solution; It is manufactured in ;(
b) Contact the continuous polyacrylonitrile aquagel film with the solution and place it into the polyether-aquagel, either sequentially or simultaneously. Stretching the PAN film system to orient the polyacrylonitrile film;
and (φ) This oriented film is dried until at least substantially the water is removed and a polyether absorbent film is obtained.

This method is particularly suitable for adsorbing water-compatible polyethers in the PANK section by maintaining the polyether at a predetermined VC degree in a water bath under steady-state process conditions. The aquagel film is passed into a water bath with a virtually constant volume of water. The polyether impregnating agent is thereby coated onto the film. The impregnating agent may be added to the water bath in a constant flow consisting primarily of 1 liter. The polyether may be added directly to the undiluted bath and additional water may be injected into the process as needed.The polyether, alone or as an aqueous solution, can be sprayed, It can be applied to the PAN film by any means including roller-brush.

The polyethers contemplated herein are at least 194
Known since the 00's. These polyethers are prepared by adding a mixture of alkylene oxides containing primarily monoethylene oxide and 1,2-propylene oxide in an oxide ratio of 75-25 to 10-90 to one or more monohydric aliphatic alcohols. It is a mixture of monohydric alcohols obtained by In addition, the oxide ratio is ethylene oxide''
It may be from 3 to 9 parts by weight of propylene. These ratios are determined by the aforementioned molecular ranges and at least practical water solubility or water affinity requirements.

Alcohol or alcohols triethylene oxide and 1,
The reaction that occurs with 2-propylene oxide 9 appears to be a simple addition reaction in which the alkylene oxide molecule undergoes a transformation to form the corresponding molecule described for any given molecule by the general formula below. Becomes an oxyalkylene group: ROH 1y (C2H40) 1z (CH3C2H30) →
R(OCnH2n)XOh where -FtOH is one or more aliphatic monohydric alcohols and X and 2 are ethylene oxides 9 and 1
, 2-propylene oxide, respectively, where n is both 2 and O in a single molecule, the total multiple where n has a value of 2 is equal to y, and the total multiple where n has a value of 6. is equal to 7, and X is the total number of such oxyalkylene groups and is equal to V+Z.

From these properties and average molecular weight, scrap index, density, viscosity, rate of viscosity change with temperature change, and theoretical considerations, these products have polyoxyalkylene chains of different lengths in different internal morphologies. Monohydroxy having a hydroxyl group found at one end of the chain and an aliphatic group of the starting alcohol or starting alcohols at the other end, and containing both an oxyethylene group and an oxy-1-2, propylene group in a single molecule. , lvlioxyalkylene flit II/
j It appears to be a complex mixture of 1M monoethers. These compounds are said to be mixtures of monohydroxy oxynigelene oxy-1,2-propylene aliphatic monoethers. The term ゛°uneven'J (beter
By 'ized)' we mean that these monoethers undergo a change in internal form from molecule to molecule; such changes occur, for example, in ethylene oxide and 1,2-propylene oxide9 and aliphatic monohydric alcohols (singular or oxyethylene group and oxy-1
, 2-propylene groups, resulting in disordered distribution.

The use of the term "heterogeneous" is not meant to exclude the presence of relatively small blocks of polyethylene oxide groups as well as relatively small blocks of polyoxy-1,2-propylene oxide groups.Mixed aliphatic When alcohol initiators are used in the production of these materials, these compounds have also been collectively referred to as polyalkoxylated, d+1 ethers.

For a more detailed description of the material contemplated by the present invention and its method of manufacture, reference is made to U.S. Pat.
No. 1.427 - incorporated herein by reference. Particularly preferred for use as adhesion strengtheners and BJ plastics for PAN are initiators - butyl algol,
Mata is a mixed polyether formed from a mixture of ethyl alcohol and toptyl alcohol.

As previously mentioned, the adhesive system of the present invention can be used to bond polyacrylonitrile films to other polyacrylo-trile films or plastic heat-sealable polymer films.

% preferred are polyolefins. Polyolefins useful herein include film-forming clasps of one or more 02-C8 alpha olefins, such as ethylene, propylene, phthene-1, pentene-1, hexene-1, heptene-1, octene-1, etc. Including homopolymers or copolymers. Useful polyolefins also preferably contain up to 20% total amount of stern t 5
i: Comprising a film-forming copolymer of one or more alpha olefins copolymerized with an alpha olefin and a monomer polymerizable with up to % by weight of one or more monomers. Examples of such monomers are - carbon oxide; sulfur dioxide; acrylic acid and/or acrylate esters such as methyl acrylate, amyl acrylate-1, hexyl acrylate, cyclohexyl acrylate - and the like; methyl methacrylate, ethyl methacrylate, propyl methacrylate , methacrylic acid or methacrylate esters such as butyl methacrylate, amyl methacrylate, and the like; include.

Methods of polymerization of alpha olefins and copolymerization of alpha olefins with other monomers such as those cited herein are well known and do not form part of this invention. The d+)olefins useful in the present invention can be atactic, isotactic, syndiotactic, crystalline or amorphous or a combination of any of the foregoing.

Preferably the polyolefin film is a homopolymer and a copolymer of ethylene and propylene. A particularly preferred polyolefin film is a random copolymer of pro-olene and low-H ethylene (commercially available as Ex-24 from Exxon Corporation). Good adhesion is obtained without surface treatment of the films of the invention. However, better adhesion may be obtained by corona discharging the polyolefin film prior to application of the adhesive and/or by other equivalent means.

The adhesive system of the present invention must not only be an effective adhesion to PAN films, but also an effective bonding system to thermoplastic moisture barrier films under the conditions of the present invention.

Although not completely understood, the presence of a heterogeneous polyether in a PAN film creates a significantly stronger bond between the PAN and adhesive system than the absence of a heterogeneous polyether in a PAN film. occurs at the interface of

The adhesive system is a combination of a commercially available product sold under the name Ail of Kraton 1000 series products (Shell Chemical Co., Polymer Division) and a second component. Something in this series 1 ~ Kraton 1102
is a styrene-butadiene block copolymer with the following properties: tensile strength 4600 psi; 300% modulus 400 psi; elongation 880%; Shore hardness A62; Right angle tear strength -Dai C, '190 Puri;
Specific gravity: 0.94; Solution viscosity - 25% w, cps, from toluene solution, 1200°. The second component of this adhesive combination is 60 to 40 parts by weight of 1.3-:phthalene;
It is a resinous random terpolymer containing 60 to 40 parts by weight of monocyclic chiluine; and 25 to 65 parts by weight of alpha methylstyrene. A preferred monocyclic compound for use in this combination is betaphelanthrene, but other monocyclic compounds or mixtures thereof may also be included. These include diintene, alpha-terpinene, beta-terpinene, alpha-ferrant-9-ene, gamma-terhinene-terepirene, sylvestrene, origanene, pyronene, and the like.

Ternary polymerization additives having the following properties are preferred): Melting point range (ring and ball) 75-125°C Ratio 1.08-0.90 Bromine number 6-14 Iodine number 79 Acid number 1 or less Saponification number 1 or less Decomposition temperature (in air) 300'C Color (in 50% toluene solution) Cardner 6 and viscosity
(in toluene) 70% Particularly preferred random terpolymers are 37.5% by weight
1, 3--<37.5 Jj by combining a feed stream containing % beta-ferrant 9, and 251 L% alpha-methylstyrene in a toluene diluent in the presence of an aluminum chloride catalyst. be done.

A tertiary lf polymer containing 64% by weight of 1.ro-pentadiene, 36.5% by weight of beta-pheranthrene, and 29.5% by weight of alpha-methylstyrene. is molecule-1ri, (average) 1880.
Bromine number 14-iodine number 79, glass transition temperature 68°C, viscosity in toluene 70%, f vs. g, and decomposition temperature (in air) 600°C. The individual films that make up the laminates described herein have thicknesses that vary widely, such as from 0.1 mil to 1° mil and preferably o.
It can be made from 5 mils to 5 mils. The thickness of the adhesive layer should, of course, be no thicker than necessary for the intended use. In some cases, the thickness will be in the micron range, although for other purposes the thickness may vary from a few mils to more than 1 mil.

The layers that make up the laminate of the present invention may be assembled in a variety of ways. For example, a combination adhesive, a styrene-butadiene block copolymer mixed with a random ternary polymer, may be deposited onto the PAN film in a suitable solution such as toluene. A second PAN film is then applied to the interfacial layer with an adhesive film, and this contact can be effected by the use of appropriate pressure and/or heat.

Alternatively, the two PAN films may be separately coated with Vcm adhesive and then secured together using pressure and/or heat, the second layer being laminated being a thermoplastic film of the type previously described. When the bonding adhesive is applied to this layer from a solvent solution, the PAN film can be brought into intimate interfacial contact in a suitable manner by moderate use of pressure and/or heat.

After the layers of the invention have been laminated onto each other - these layers can be formed into a suitable container. For example, they can be made into retort pouches using known methods. Following this method, the laminate can be folded with the heat poolable polyolefin sides facing each other, and these are hemmed and sealed between hot plates. The H ceriacrylonitrile side is ! Since it can be heat sealed in one step and requires only one step, the edge, i-
II y // 1. (14g and LILIσ) 4 Must Meng 1 or H: Bio Sen Hego Shi6ζ can be done.

EXAMPLE A strip of 6 mil thick corona-treated film consisting of a random copolymer of propylene with a small amount of ethylene (commercially available as EX-24 from Ekun Corporation) was mixed with 6 parts by weight of a styrene-butadiene floc copolymer. and 1 part by weight of a ternary compound consisting of 1 part by weight and 1 part by weight of a ternary 11 compound consisting of 1 part by weight of 1,3-<ncdien-36.5 Mftft+s and 295 parts by weight of alpha methyl styrene at 25 parts by weight solids. coated with a toluene solution containing %. This layer is 200
Dry at °F for 20 seconds. A corresponding strip of biaxially oriented polyacrylonitrile homopolymer film approximately 0.65 mil thick was prepared. The film contained 14% polyether within the polyether range defined herein. This polyether is Tsururacol W
-660 and can be obtained from BAS F Ryant Co., Ltd. This strip was applied to an adhesive coated propylene and ethylene copolymer. The laminate films were pressed together with a suitable pressure sufficient to create substantially uniform interfacial contact between the films. The laminate was then heated to 250°F for 15 seconds. This resulted in a laminate that could not be peeled off without considerable force. When laminating polyacrylonitrile films without heterogeneous polyethers of the present invention to other PAN films or polyolefin films, the adhesives of the present invention do not result in strong and effective laminates compared to PANs containing heterogeneous polyethers. Will.

Applicant: Mobil Oil Corporation (
(4 people outside)

Claims (1)

[Claims] 1 (α) ethylene oxide and propylene oxide
At least 1 having 10 aliphatic carbon atoms
A stretched polyacrylonitrile film containing a fixed proportion of a liquid amorphous ethylene oxide-propylene oxide co-merger obtained by reacting with a monohydric alcohol active hydrogen compound initiator; The adhesive layer is (1+1:3
A styrene-butadiene floc copolymer with a 7-mer of J13 iiJ ratio of 1 and 30 to 40 parts by weight of 1,6-butadiene-
It is a combination of a random terpolymer consisting of 30 to 40 parts by weight of terpolymer and 25 to 35 parts by weight of alpha methylstyrene; 1 to 3 parts by weight of a block copolymer part, 5 parts by weight, and (C) either the second stretched polyacrylonitrile film or the heat-sealable polyolefin film, which is in contact with the adhesive layer. A flexible laminate film consisting of . 2. The polyacrylonitrile comprises at least 80% acrylonitrile repeat units.
Laminating film as described in section. 3. The polyacrylonitrile is a homobolymer, and the laminate film shown in the range 1y)+ of the q1'' requirement. 4. The adhesive layer is made of 6 parts by weight of the styrene-tadiene block copolymer and Including the ternary-one combination of the voluminous part,
A laminate film according to claim 1. 5. The laminate film according to paragraph 4 of claim 1, wherein the chiral compound is beta-phellandrene. 6. The ethylene oxide-propylene oxide copolymer is water-soluble or water-miscible, and has an average molecular weight of 5007;
7. The laminate film according to claim 1, wherein the monovalent initiator is methanol, ethanol, bronoξol. 1 separated from the group consisting of and butanol
7. The laminate film according to claim 6, which is one or more -q'. 8. The ethylene oxide-propylene oxide co-Oxide is present in the polyacrylonitrile film in an amount of at least 1% by weight.
Laminating film as described in section. 9. The ethylene oxide-propylene oxide co-vertical is present in 5 to 20% by weight of polyacrylonitrile;
A laminate film according to claim 8. 1.0. 171. The laminate film of claim 1, wherein the heat-sealable polyolefin film is a homo, I solymer 8 or copolymer of a -C alpha olefin. The laminate film of claim 411J, paragraph 10, wherein the polyolefin film comprises up to 2011% of one or more monomers copolymerizable with alpha-olefins. 12. The laminate film according to item 11, wherein the polyolefin film contains not more than 5% of one or more other monomers that can be combined with the alpha olefin. 13 Polyolefin film is one ethylene material:
The laminate film according to claim 11, which is a homopolymer of propylene or a comonomer of ethylene and propylene. 14.2 or more polyacrylonitrile films are produced by laminating one polyacrylonitrile film and a heat-sealable polyolefin film, and (α) the above-mentioned polyacrylonitrile film contains:
1 to 10 ethylene oxide and propylene oxide
A liquid asymmetric ethylene oxide-propylene oxide copolymer obtained by reacting an active hydrogen compound initiator of at least one monohydric alcohol having 1 carbon atoms
1. (h) (]) 1 styrene-butadiene copolymer having monomers in a weight ratio of 1: to 3:1; J/Butadiene 30 to 4D.i bone monocyclic terzun and 25
~65 city J1: A layer of an adhesive composition consisting of a combination of random ternary 1f1 combination consisting of alpha methyl styrene is placed between each of the films, and this silk combination is mainly composed of 1 part of A method consisting of each step of applying pressure or pressure and heat to the film surface. 15. The pressure is at least sufficient to form an intimate interfacial contact between the film and the first self-adhesive composition. Claim 14 for aspect 1, characterized in that the bonding is characterized by applying the composition from a solvent solution of the adhesive composition to one or both films, evaporating the solvent, bringing about interfacial contact and heating the laminate. the method of. 17. The pouch product manufactured by Soft Bond Filmka et al. as set forth in claim 1 or '? i.Product.