JP2971877B1 - Food packaging film and packaged food - Google Patents

Abstract

A food containing a cyclodextrin derivative which has excellent barrier properties, has compatibility (compatibility) when mixed with another resin, and does not significantly reduce transparency, processability or structural characteristics. Provide packaging film and packaged food. A barrier film compound comprising a thermoplastic polymer and a thermoplastic web comprising a dispersed cyclodextrin compound having a substituent compatible with the cyclodextrin in the film, wherein the thermoplastic / cyclodextrin film comprises a film material. By the interaction between the substituted cyclodextrin and the permeable substance contained in
Substantial barrier properties can be obtained. Substituents on the cyclodextrin molecule render the cyclodextrin dispersed and stable, thereby providing an extrudable thermoplastic. Such materials are used as single-layer films or multilayer laminated films.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a thermoplastic polymer composition having barrier properties, which can be used as a packaging material. The thermoplastic barrier material is
It may be formed into a barrier coating, a flexible film, a semi-rigid sheet or a rigid sheet or rigid structure. The thermoplastic barrier material may also include the barrier forming material as a component and may be a coating formed from an aqueous solution, solvent solution or suspension of the thermoplastic film forming material. Such film sheets and coating materials are made of various permeable substances (perme
Acts as a barrier to ant). Examples of the permeable material include water vapor, aliphatic hydrocarbons, aromatic hydrocarbons, aliphatic halides, aromatic halides, heterocyclic hydrocarbons, alcohols, aldehydes, amines,
Examples include organic substances such as carboxylic acids, ketones, ethers, esters, sulfides, thiols, and monomers, and off-flavors and malodors. The thermoplastic barrier composition of the present invention is formed into a useful film, sheet, structure, or molded body by extrusion molding, lamination molding, cast molding, etc. using conventional processing techniques. be able to. In addition, single, double and multilayer films can be coated, printed or embossed.

[0002]

BACKGROUND OF THE INVENTION The development of packaging film materials, semi-rigid or rigid sheets or rigid structure containers made of thermoplastic compositions has received considerable attention. In such applications, the polymer composition serves as a barrier to the ingress of various osmotic components, i.e., to prevent contact between the contents of the package and the osmotic material. Improving barrier properties is an important goal for film and thermoplastic manufacturers.

[0003] Barrier properties arise from both the structure and composition of the material. For example, the order of the structures, ie, the crystallinity and amorphous properties of the material, the presence of layers and protective coatings, etc., can affect the barrier properties. The barrier properties of many materials are further enhanced by the use of liquid crystal or self-ordring molecular technology, such as uniaxially aligning materials such as ethylene vinyl alcohol film or biaxially aligning nylon films. It can be improved by using a technique for obtaining a useful structure. The internal structure of the polymer may be crystalline or oriented to increase its resistance to penetration of the permeable material. Thermoplastic material or package coating material
A material that does not allow the permeable substance to be adsorbed on the barrier surface may be selected. Further, a material that can prevent the permeable substance from passing through the barrier may be selected. Fick's law (F
Infiltration corresponding to ich's law) and non-fick diffusion has already been observed. In general, penetration is a type of concentration and temperature dependent passage action.

[0004] The infiltration process is described as a multi-step process. First, the permeable molecule collides with the polymer and is absorbed into the polymer. Next, random movement of the osmotic molecule occurs, and the molecule moves through the polymer matrix (migration t
hrough) and finally the osmotic molecules are released from the polymer and the process ends. This process occurs to eliminate the chemical concentration differences that exist between the outside of the film and the inside of the package. When an organic molecule penetrates a packaging film, it involves two components, the diffusivity, and the solubility of the molecule in the film. Examining the diffusivity gives the rate at which molecules pass through the film. The rate affects whether the permeable molecule is likely to move through the polymer. Solubility is a measure of the concentration of permeable molecules that may be in a position to move through the film. Diffusion and solubility are important measures of barrier film performance. There are two mechanisms by which organic vapors penetrate the packaging film and move in large quantities. It is capillary flow and activated diffusion. Capillary flow involves the penetration of small molecules through pinholes and highly porous media. Of course, this property is not desirable for high barrier films. The second phenomenon, called activated diffusion, is a phenomenon in which osmotic molecules are efficiently absorbed and dissolved in the non-porous film at the influent surface, and diffuse through the film under a concentration gradient (from high to low concentration), causing a low Indicated to be released from the effluent surface at a concentration. For non-porous polymer films, bulk transport of osmotic molecules therefore consists of three steps: absorption, diffusion and desorption. Absorption and desorption depend on the solubility of the osmotic molecules in the film. The process by which the polymer absorbs the vapor is thought to consist of two stages. That is, the vapor on the polymer surface is concentrated, and the concentrated vapor is dissolved in the polymer. For thin film polymer films, permeation is the flow of material through the film under an osmotic gradient. The penetration promoting force is provided as the pressure difference between the osmotic molecules on both sides of the film. A number of factors determine the ability of a permeable molecule to penetrate through a thin polymer film. The factors are, for example, size, shape, chemical properties of the permeable material, physical and chemical properties of the polymer, and interactions between the permeable material and the polymer.

[0005]

The permeable material (synonymous with permeable material) used in the present invention is present in the atmosphere at a substantially detectable concentration and is capable of passing through known polymer materials. It shows what is. Indeed, various penetrants are known. Such penetrants include water vapor, aromatic and aliphatic hydrocarbons, monomer components and their residues, off-flavors, malodors, perfumes, smoke, insecticides, toxic substances And so on. Typical barrier materials are polymer films made by single-layer, two-layer coextrusion or lamination of the polymer, coated single-layer, double-layer, or once or both sides of one or both sides of the film or sheet. It consists of a multilayer film coated the above number of times.

The two most widely used barrier polymers for food packaging are ethylene vinyl alcohol copolymer (EVOH) or ethylene vinyl acetate copolymer (EVA) and polyvinylidene chloride (PVDC). Other useful thermoplastic resins include, for example, ethylene acrylic materials including ethylene acrylic acid, ethylene methacrylic acid, and the like. Such polymers are also commercially available and include gases,
It has some resistance to penetration of flavors, aromas, solvents and most chemicals. PVDC
Is also excellent in blocking moisture, whereas EVOH is excellent in processability and can be used substantially as a recycled material. EVOH copolymer resins have grades with various ethylene concentrations and are widely applied to various uses.
As the ethylene content decreases, the barrier properties to gases, flavors, and solvents increase. EVOH resin
It is generally used as a composite extruded product with polyolefin, nylon, or polyethylene terephthalate (PET) as a support layer (structure layer). Commercially, amorphous nylon resins have been modified for use in single layer bottles and films. Moderate barrier polymer materials such as single layer polyethylene terephthalate, polymethylpentene or polyvinyl chloride can also be used.

[0007] At present, various techniques for improving the barrier properties are of interest. There is increasing research into the use of physical packaging barriers as active chemical barriers or hermetic packaging materials. Of particular interest are the use of certain copolymer and terpolymer materials, the use of certain polymer alloys, and the use of improved coatings as barrier materials such as silica metals and organometallics.

[0008] Another important barrier technique involves the use of oxygen absorbers and scavengers in the polymerized coating or bulk polymer material. A metal reducing agent such as a ferrous compound, powdered oxide, or metal platinum may be introduced into the barrier device. With such an apparatus, oxygen is converted into a stable oxide in the film and collected. Non-metallic oxygen scavengers have also been improved and are used to reduce problems with metallic or metallic tastes and odors. Such devices include compounds such as ascorbic acid (vitamin C) and salts. Recent studies have introduced organometallic molecules that have an affinity for oxygen. Such molecules remove oxygen from the inner or enclosed space of the packaging material and absorb the oxygen molecules into the inner polymer chemistry.

[0009] Scientists and engineers involved in packaging
In order to obtain higher barrier properties, materials have been blended and new polymer films, coated films, polymer alloys, etc. have been developed. While such devices have met with some success in practicality, they have had virtually no commercial success due to a number of factors, such as obtaining barrier properties at low cost.

One problem that arises when searching for a polymer blend or compound of a polymeric material relates to the physical properties of the film. The film must retain substantial clearness, tensile strength, penetration resistance, tear resistance, etc., for use as a packaging material.
Blending unfavorable materials to the thermoplastic prior to film extrusion would substantially reduce the properties of the film. A compatible polymer material for the polymer alloy;
To find compatible additives for polymeric materials,
The suitability must be proved by experiment, and theorization is difficult.
However, compatibility can be demonstrated by using conventional test methods to show compounds that have improved barrier properties with little loss of clarity, processability or structural properties.
Thus, in practice, it may be sufficient to show that a thermoplastic material for packaging has been developed that can be introduced into a polymer material to provide excellent barrier properties without significantly impairing the structural properties.

In order to solve the above-mentioned conventional problems, the present invention has excellent barrier properties, has compatibility (compatibility) when mixed with other resins, and has markedly reduced transparency, processability or structural properties. It is an object of the present invention to provide a food packaging film and a packaged food containing a cyclodextrin derivative, which does not have any problem.

[0012]

According to the present invention, there is provided a food packaging film comprising a thermoplastic film composition having improved barrier properties, comprising: A thermoplastic film comprising: a thermoplastic polymer; and (b) a polymer compatible cyclodextrin derivative in an amount that is uniformly dispersed in the polymer and effectively absorbs the penetrant, wherein the cyclodextrin is substantially free of mixed complex compounds. It is a composition.

[0013] In the film, the permeable material may include a residual polymer volatile material. The food to be packaged may be a liquid food.

In the film, the thermoplastic polymer may be a vinyl polymer containing an alpha olefin. Further, in the film, the thermoplastic polymer may be a chlorine-containing vinyl polymer containing vinyl chloride or vinylidene dichloride.

In the above-mentioned film, the thermoplastic polymer may be poly (vinyl chloride-co-vinyl acetate) or poly (vinyl chloride-co-vinylidene dichloride).

In the film, the thermoplastic polymer may be polyvinyl alcohol, poly (ethylene-co-vinyl alcohol), or poly (ethylene-co-methyl acrylate).

In the above-mentioned film, the cyclodextrin derivative preferably contains a β-cyclodextrin derivative. In the film, the cyclodextrin derivative may have at least one substituent on the cyclodextrin primary carbon atom.

In the film, the cyclodextrin may be α-cyclodextrin, β-cyclodextrin, γ-cyclodextrin, or a mixture thereof.

In the film, the thermoplastic polymer preferably contains 0.1 to 5% by weight of a polymer-compatible cyclodextrin derivative. In the film, the thermoplastic polymer may be a polyester. Polyester includes poly (ethylene-co-terephthalate).

In the film, the thermoplastic polymer may be polyethylene. Polyethylene includes high density polyethylene. Next, the packaged food of the present invention is characterized by being packaged with the food packaging film according to any one of claims 1 to 14.

We have already formed a barrier layer having a compatible cyclodextrin derivative dispersed in a polymer, thereby providing a barrier property of a thermoplastic polymer without a significant decrease in transparency, processability or structural properties. Has been found to be improved. We have 2
Two examples have been developed. The first relates to barriers made using thermoplastic technology involving cyclodextrin derivatives. The second is a coating obtained by casting a solution or suspension of a film-forming or polymer-forming material combined with a cyclodextrin derivative to form a barrier layer. Without compatible substituents, cyclodextrin derivatives cannot be fully compatible with bulk materials, resulting in a clear and useful barrier layer or packaging material. The compatible cyclodextrin derivative is a mixture complex (i
nclusion complex).
In the present invention, “contains almost no inclusion complex” means that most of the dispersed cyclodextrin derivatives in the film contain a cyclodextrin ring having no permeable substance inside the cyclodextrin molecule. The cyclodextrin compound is added uncomplexed, but some synthesis occurs during the manufacturing process due to polymer degradation or paint or coating compositions. The internal cavity of the cyclodextrin is
Keep unblocked by complex molecules.

Cyclodextrin derivatives have a substituent attached to a cyclodextrin molecule that is compatible with the polymer material. Cyclodextrins are cyclic dextrin molecules with 6 or more glucose moieties in the molecule. Cyclodextrin is α-cyclodextrin (αC
D), β-cyclodextrin (βCD), γ-cyclodextrin (γCD), or a mixture thereof. The present inventors have found that derivatization of a cyclodextrin molecule is important for the formation of a cyclodextrin material. It can be effectively blended with the thermoplastic bulk polymer material without compromising clarity, processability or structural properties or package properties. As the substituent of the cyclodextrin molecule, one whose component, structure, and polarity match the component, structure, and polarity of the polymer is selected. By doing so, the cyclodextrin is fully compatible with the polymeric material. In addition, derived cyclodextrins are blended with thermoplastic polymers and formed into films or semi-rigid or rigid sheets or other rigid structural materials by conventional thermoplastic manufacturing techniques. The present inventors have discovered that cyclodextrin materials can be used to form such thermoplastic barrier structures without substantially reducing structural properties. The film provides an odor control valve and barrier to separate contaminants from the polymer matrix and product storage, and can protect the environment. Thermoplastic polymers used in the production of packaging film materials are typical products obtained by polymerizing monomers resulting from a purification process. Purified fluids used in the polymerization chemistry industry all contain residual monomers, trace amounts of purified hydrocarbons, catalysts and catalyst by-products as impurities in the polymer matrix. In addition, the environment in which materials are packaged, stored, and used after manufacture often contain some percentage of contaminants that penetrate barrier films and barrier sheets and contaminate food and other contents. . Volatiles of the residual polymer are synthesized by dispersing the cyclodextrin into the molten film polymer using an extruder. Cyclodextrin (CD)
The residence time or mixing time of the molten polymer and the molten polymer in the barrel of the extruder precedes the synthesis of residual polymer volatiles.
It is believed that uncomplexed cyclodextrin dispersed within the polymer remains with the environmental pollutants diffused through the polymer. The cyclodextrin remains widely not only between polymer molecular chains but also in cavities between polymer chains. As the osmotic material is dispersed through the polymer on the tortuous path, the non-synthetic cyclodextrin can be conjugated to the osmotic agent molecules when dispersed within the film. Subsequent synthesis and release of the same osmotic molecule between the cyclodextrin molecules of the film is possible. In other words, the cyclodextrin diffused into the film continues to synthesize and release. The diffusivity can be increased by the number and size of the holes created by the presence of cyclodextrin. The modified cyclodextrin desirably has chemical properties such as size and shape that are compatible with the polymer and do not adversely affect the barrier properties of the film.

The advantages of cyclodextrin over other high barrier property film technologies are twofold. For one, cyclodextrin can be synthesized with residual organic volatile contaminants inherent in all polyethylene and polypropylene packaging films. Second, cyclodextrins have the unique ability to synthesize with osmotic molecules. Without this, the osmotic material would pass through the film addition modifier of the package and would jeopardize product quality and safety.

Since all packaging films pass organic vapor, it is important to measure the amount of permeation into the film at a predetermined time in order to know the performance of a specific packaging film. The above infiltration process is fast for low water activity foods (crackers, cookies, cereals). The infiltration process is
It will be faster or slower depending on the relative humidity outside the package and the storage temperature of the product. As the relative humidity outside the package increases, the pressure difference inside and outside the package increases. The greater the pressure difference and / or the higher the temperature, the faster the organic penetrant diffuses into the film. The method used to test the film sump in this study required the worst case (60% relative humidity outside the package and 0% water activity inside the package) to provide fast test results. The storage condition was used. The organic permeation concentration used here is the ink used to print on the packaging material, the additives used in polymer or paper or foil lamination or gasoline,
Obtained from foods contaminated with diesel fuel, paint solvents, detergents, synthetic flavors, foods and more. Relative humidity, water activity and osmotic concentration are used in testing a number of high barrier films currently used in industry. The test can effectively demonstrate the performance differences between the various high barrier films. There are four test parameters that are important for high barrier film performance. First
Is the time required for the penetrant to begin diffusing into the package, the so-called "lag time". The second is the rate at which the penetrant diffuses into the film, the third is the total amount of penetrant that can pass through the film in a given time, and the fourth is how effective the barrier is against penetration of the penetrant. is there.

The present inventors have also found that by adding a cyclodextrin derivative to the thermoplastic material of the present invention, properties such as surface tension and electrostatic properties can be improved. Such properties make it easier to apply this barrier material to coatings and printing. Cyclodextrin derivative materials can be added to various thermoplastic films and sheets.

[0026]

BEST MODE FOR CARRYING OUT THE INVENTION (1) Film A film or sheet is an unreinforced portion of a thermoplastic resin, and has a very small thickness compared to its width and length. Typical film thicknesses are 0.25 mm, typically 0.01-20 mm. In the case of a sheet, the thickness is 0.
25 mm to several centimeters, typically 0.3 to 3 m
m. The film or sheet can be used alone or in combination with other sheets, fabrics, structural units by lamination, coextrusion, or coating. In the present invention, the term web is a film,
Sheet, semi-rigid sheet and rigid sheet, and rigid unit after formation. Important properties are tensile strength,
Mean elongation, stiffness, tear strength, and resistance. Other characteristics include optical characteristics such as haze and transparency. It also includes chemical resistance such as water absorption and permeability of various permeable substances including water vapor, electric properties such as electric conductivity, and permeation properties such as shrinkage, cracking and weather resistance.

Thermoplastic material is blown thermoplastic extrusion molding
Barrier films using various processes such as (blow thermoplastic extrusion), extrusion linear biaxially oriented film molding, and casting from molten thermoplastic, monomer or polymer (aqueous or organic solvent) suspensions. Formed. These methods are themselves well-known manufacturing methods. The characteristics of polymeric thermoplastics that have led to successful barrier film formation are described below. Those skilled in the manufacture of thermoplastics will be aware of the molecular weight (in the thermoplastics industry, the melt index is a measure of molecular weight; melt index refers to molecular weight, density, etc., according to the thermoplastic process and the particular end use intended). ,
And the degree of crystallinity. It is well known to tailor polymer materials by controlling ()). For blow thermoplastic extrusion molding, polypropylene, nylon, nitrile, PETG and polycarbonate are sometimes used for forming blown films, but polyolefins (LDPE, LLDP)
E, HDPE) is the most commonly used thermoplastic polymer. A typical polyolefin has a melt index of 0.2 to 3 grams / 10 minutes, a density of about 0.910 to about 0.940 grams / cc, and a molecular weight of about 200,0.
00 to 500,000. For biaxially oriented film extrusion, the most commonly used polymers are olefins, mainly polyethylene and polypropylene (melt index about 0.4-4 grams / 10 minutes, molecular weight about 200,000-600,000). Polyester and nylon may be used. For casting, a molten thermoplastic resin or monomer suspension is typically produced from polyethylene or polypropylene. Occasionally, nylon, polyester and PVC are also cast. For roll coating of aqueous dispersions based on urethane acrylates and PVDC, the dispersions are polymerized before coating to maximum crystallinity and molecular weight.

Various types of thermoplastic materials are used in forming film and sheet products. Examples of such materials include polymethyl methacrylate, poly-n
Poly (acrylonitrile-co-butadiene-co-styrene) polymers, such as -butyl-acrylate, poly (ethylene-co-acrylic acid), poly (ethylene-co-methacrylate), etc .; acrylic acid polymers; cellulose acetate, cellulose acetate Cellophane and celluloses including propionate, cellulose acetate butyrate and cellulose triacetate; polytetrafluoroethylene (Teflon (trademark of DuPont)), poly (ethylene-co-tetrafluoroethylene) copolymer, (tetrafluoroethylene-co Fluorinated polymers including propylene) copolymers, polyvinyl fluorinated polymers, etc .; polyamides such as nylon 6, nylon 6,6 etc .; polycarbonates; poly (ethylene-co-terephthalate), poly (ethylene). Polyesters such as N-co-1,4-naphthalenedicarboxylate), poly (butylene-co-terephthalate); polyimide materials; polyethylene materials including low-density polyethylene; linear low-density polyethylene, high-density polyethylene; Polypropylene, biaxially oriented polypropylene; polystyrene, biaxially oriented polystyrene; vinyl film, for example, polyvinyl chloride, (vinyl-chloride-co-vinyl-acetate) copolymer, polyvinylidene chloride, polyvinyl alcohol, (vinyl) −
Chloride-co-vinylidene-dichloride) copolymers, special films such as polysulfone, polyphenylene sulfide, polyphenylene oxide, liquid crystal polyester, polyether ketone, polyvinyl butyral, and the like.

[0029] Films and sheets are typically manufactured using thermoplastic techniques such as melt extrusion, calendering, solution casting, and chemical regeneration processes. Many manufacturing steps involve uniaxial or biaxial orientation processing. Films and sheets are mostly produced by melt extrusion techniques. In the melt extrusion, the material is heated to a temperature higher than the melting point in the extruder, and a typical extruder (extruder) has a material supply unit 27, a melting zone 28 and an extruder 29.
The melt is introduced into a slot die where the sides are thin and flat, and are rapidly cooled to a solid and oriented. Generally, the extruded hot polymer film is cooled rapidly on rolls or drums or by a stream of air.
Finally, a quenching bath may be used. Thermoplastic material is also blown. In FIG. 2, the hot melt polymer is extruded from the annular die 22 as a tube form 21. The tube is inflated by air (see air inlet 26), the diameter of which is determined by consideration of the desired film properties and actual handling. As the hot melt polymer exits the annular die, the extruded hot tube is expanded by air to 1.2-4 times the original die diameter. At the same time, by means of cooling air (see air flow inlet 20), a hollow, tubular section 21
The web forming an extruded solid with is cooled. The film tube is collapsed in a V-shaped frame 23 and sandwiched between the ends of the frame (nip rolls 24) to trap air in the thus formed closed area. Rolls 24 and 25 take up the film produced from the tube that is continuously extruded from the die.

In preparing the biaxially oriented film and producing the blown thermoplastic film, the present inventors have determined that the melting temperature and die temperature can be adjusted to achieve the desired permeability or penetration rate for the film of the present invention. I found something important. Thereby, melt damage can be reduced and the uniformity of the film can be improved (surface defects can be suppressed).
According to FIG. 2, the temperature of the melt in the melting zone 28 is 390-
420 ° F (198-216 ° C), preferably 395-
415 ° F (202-213 ° C). The temperature of the extrusion die 29 is 400-435 ° F (204-224).
° C), preferably 410-430 ° F (210-221 ° C).
° C). The extruded polymer is cooled using a circulating water bath or circulating air. The extruder can be controlled according to the production volume. By doing so, the production rate is maintained while the polymer is sufficiently heated until it melts and the required die temperature is obtained. If the film of the present invention is produced at such a temperature, the cyclodextrin material is sufficiently compatible with the thermoplastic melt, the quality is not degraded by the high temperature, it is clear, compatible, and a useful barrier film. Is reliably manufactured.

Often, two thermoplastic materials are combined in a co-extrusion process to produce a film or sheet for a particular end use. Extruding one or more types of polymer present in one or more layers of the melt simultaneously with a co-extrusion die results in a film having multiple properties of both layers. Layers of different polymers and different resins are combined by blending the materials in the melt before extrusion or by extruding different thermoplastics in parallel. The melt flows on the die in a layered manner and flows onto the cooling drum. The film is processed according to conventional methods and orients after cooling. The film may contain additives such as antioxidants, heat stabilizers, UV stabilizers, leveling agents, fillers, and anti-block agents.

The barrier layer of the present invention comprises an aqueous dispersion of a film-forming polymer and a cyclodextrin derivative,
It can be produced by casting a solvent dispersion or solution. At this time, the aqueous or solvent-based material may be formed by a generally employed method. For example, commercially available polymers, polymer dispersions, polymer solutions or polymers may be used, or both common aqueous or solvent treatment techniques may be used. The cyclodextrin derivative material may be used in combination with an aqueous or solvent-based dispersion or solution to form a film or to coat a formed film. Such a barrier layer or barrier coating may be formed by a general coating forming technique such as roller coating, doctor blade coating, or spin coating. Such a coating may be applied to or removed from the surface first, and generally the coating is formed on a thermoplastic or thermoset polymer web and held there for use in packaging. Serves as a barrier layer on the web. Ordinary coatings may be made in much the same way as the same thermoplastic polymers used in film sheets and other structural layers, with the addition of a cyclodextrin derivative material extender. The barrier layer or barrier coating formed using the film-forming polymer and the cyclodextrin derivative may be used as a single coating layer or as a multilayer coating layer. The multilayer coating layer has a barrier layer or coating on one or both sides of the support film or sheet, and may be used with other coating layers such as print layers, clear coating layers, such as conventional packaging, food packaging, consumer goods packaging, and the like.

(2) Cyclodextrin The thermoplastic film of the present invention contains a hanging portion (pendent moieties) or a cyclodextrin having a substituent, and a cyclodextrin material is formed by the hanging portion or the substituent. Compatible with thermoplastic polymers. In the present invention, the compatibility means that the cyclodextrin material is uniformly dispersed in the molten polymer, traps or synthesizes permeable substances and polymer impurities, and remains without essentially impairing the properties of the polymer film. It means what you can do. Thus, compatibility has the same meaning as compatibility. Compatibility can be found by examining polymer properties such as tensile strength and tear strength, permeability or permeability of permeable material, surface smoothness, clearness, and the like.
The use of incompatible derivatives significantly reduces polymer properties, results in very high permeability or transmission, and results in a rough and less clear film. Qualitative compatibility screening is performed on small batches (from 100 grams to 100 grams).
1 kilogram of thermoplastic and substituted cyclodextrin). The blended material is extruded at the manufacturing temperature and has a diameter of about 1-5 m.
m linear strand molded product. Since incompatible cyclodextrin materials do not disperse uniformly in the melt, it can be seen by observing the clear molten polymer just extruded from the extrusion head. We believe that the incompatible cyclodextrin degrades at the extrusion temperature,
It has been found that when extruded, it emits a characteristic odor like "burnt flour". In addition, incompatible cyclodextrins have been found to cause substantial melting cracks in the extrudate that are observable to the naked eye.
Finally, the extrudate is cut into small pieces, cut sideways, and inspected using an optical microscope. Then, incompatible cyclodextrins contained in the thermoplastic matrix are clearly observed. Cyclodextrins are cyclic oligosaccharides composed of six or more glucopyranose units linked by an α (1 → 4) linkage. Cyclodextrins with up to 12 glucose residues are known, but 6, 7 and 8
The three most common homologs (α-cyclodextrin, β-cyclodextrin, and γ-cyclodextrin) with the following residues are used.

Cyclodextrin is produced by highly selective enzymatic synthesis. Consists of 6, 7, or 8 glucose monomers arranged in a donut-shaped ring, each represented as an α, β, or γ cyclodextrin (see FIG. 1). When glucose monomers are combined in a special way, the cyclodextrin has a strong, frustoconical molecular structure with a specific volume of hollow inside. The interior cavity is lipophilic, which in turn attracts hydrocarbon materials (which are hydrophobic in aqueous systems) compared to the exterior. This is a key structural feature of cyclodextrin, which allows the synthesis of molecules (eg, aromatics, alcohols, halides and hydrogen halides, carboxylic acids and their esters, etc.). . The synthetic molecule must be at least partially sized to fit inside the cavity of the cyclodextrin. This results in an inclusion complex.

Table 1 shows general properties of cyclodextrin.

[0036]

[Table 1]

The oligosaccharide ring forms a circular surface as a truncated cone with the primary hydroxyl groups of each glucose residue located at the narrow end of the circular surface. The secondary glucopyranose hydroxyl group is located at the wide end. The parent cyclodextrin molecule, and useful derivatives thereof, can be represented by the following formula (where the carbocycle indicates conventional numbering): In the formula, the vacant bond represents the balance of the cyclic molecule.

[0038]

Embedded image

In this formula, R ₁ and R ₂ are primary and secondary hydroxyl groups, respectively. In the cyclodextrin molecule, the chemical reagent reacts with the primary hydroxyl group at the 6 position of the glucose moiety, and the reaction also occurs at the secondary hydroxyl group at the second and third positions. Due to the geometry of the cyclodextrin molecules and the chemical nature of the ring substituents, not all silodextrin molecules react the same. However, if the conditions are carefully and efficiently adjusted, the cyclodextrin molecule will react to give a derivative molecule in which all hydroxyl groups are derived with one substitution type. Its derivative is a hypersubstituted cyclodextrin. Cyclodextrins with selected substituents, in other words, those substituted only on the primary hydroxyl group or selectively substituted on one or both secondary hydroxyl groups, can also be synthesized if necessary. Is also good. The synthesis of a derivative molecule with two or three different substituents may continue. These substituents may be located randomly or directly attached to a particular hydroxyl group. In the present invention, the cyclodextrin molecule must contain sufficient thermoplastic compatible substituents on the molecule. That way, when the cyclodextrin material is uniformly dispersed in the thermoplastic and formed into a clear film, sheet or solid structure, it does not impair the physical properties of the polymer.

In addition to introducing substituents on the CD hydroxyl group, other molecules can be modified. For example, other carbohydrate molecules may be introduced into the cyclic backbone structure of the cyclodextrin molecule. An SN ₂ substituent may be substituted in place of the primary hydroxyl group, or an oxidized dialdehyde or acid group may be formed to further react with a derivatizing group or the like. Secondary hydroxyl groups may be removed after the reaction, leaving unsaturated groups. A variety of well-known reactants may be added to the unsaturated group, thereby adding or cross-linking double bonds to form derivative molecules.

In addition, one or more cyclic oxygens of the polysaccharide moiety may be opened to create reaction sites. Such techniques may be used to introduce compatible substituents on the cyclodextrin molecule.

A preferred intermediate for preparing a derived cyclodextrin material having functional groups compatible with the thermoplastic polymer involves reaction at the primary or secondary hydroxyl groups of the cyclodextrin molecule. The present inventors have found that a wide range of pendant substitution moieties on the molecule is available. Such derivatized cyclodextrin molecules include acylated cyclodextrins, alkylated cyclodextrins, tosylate, mesylate (mesylate).
ate) cyclodextrin esters such as other related sulfo derivatives, hydrocarbyl-aminocyclodextrin, alkylphosphono and alkyl phosphatocyclodextrin, imidazoyl-substituted cyclodextrin, pyridine-substituted cyclodextrin, hydrocarbyl sulfur-containing functional groups Substituted cyclodextrin (hydro
carbyl sulpher containing functional group cyclode
xtrin), silicon-containing functional group-substituted cyclodextrins, carbonate salts and carbonate-substituted cyclodextrins, carboxylic acids and related substances-substituted cyclodextrins, and the like. The replacement portion must have a region that confers compatibility to the derived material.

Acyl groups used as compatible functional groups include acetyl, propionyl, butyryl, trifluoroacetyl, benzoyl, acryloyl, and well-known organic groups. In forming such groups at the first or second ring hydroxy group of the cyclodextrin molecule, well known reactions are used. The acylation reaction is
It is carried out using a suitable acid anhydride, acid chloride, and a well-known synthetic method. Peracylated cyclodextrins can also be produced. Additionally, one or more stabilized available hydroxyl groups substituted with other functional groups may be partially substituted to produce cyclodextrin.

[0044] The cyclodextrin material may also be reacted with an alkylating agent to produce an alkylated cyclodextrin. The alkylating group reacts the available hydroxyl group with the alkylating agent under sufficient reaction conditions,
It may be a peralkylated cyclodextrin. Further, depending on the alkylating agent, a cyclodextrin molecule used under the reaction conditions or a cyclodextrin in which all available hydroxyl groups are not substituted may be produced. Typical examples of alkyl groups useful for making alkylated cyclodextrin include methyl,
General alkyl groups including propyl, benzyl, isopropyl, tertiary butyl, allyl, trityl, alkyl-benzyl and the like. Such an alkyl group may be produced by a conventionally known method. For example, it may be prepared using a conventional method in which a hydroxyl group is reacted under appropriate conditions with an alkylating agent such as an alkyl halide or an alkyl sulfate reactant.

Tosyl (4-methylbenzenesulfonyl) mesyl (methanesulfonyl), or other related alkyl or acylsulfonyl-forming reagents, may be used to make compatible cyclodextrin molecules used in thermoplastics.

The primary -OH groups of the cyclodextrin molecule react faster than the secondary hydroxyl groups. However, the molecules may be substituted at virtually any position to form a useful composition.

[0047] Such a sulfonyl-containing functional group is the primary / primary moiety of any glucose moiety of the cyclodextrin molecule.
It may be used to derive any of the second hydroxyl groups. The reaction can be performed using a sulfonyl chloride reactant. The reactants can react efficiently with primary or secondary hydroxyl groups. The sulfonyl chloride is used in an appropriate molar ratio depending on the number of targeted hydroxyl groups in the molecule that need to be substituted. Both symmetric (substituted compounds for each single sulfonyl moiety) or asymmetric (primary and secondary hydroxyl groups substituted with a mixture of groups containing sulfonyl derivatives) can be prepared using known reaction conditions. Good. The sulfonyl group may be used in combination with an acyl or alkyl group generally selected by an experimenter. Finally, in making monosubstituted cyclodextrins, the single glucose moiety in the ring can contain 1-3 sulfonyl substituents. Stable portions of the cyclodextrin molecule other than the mono-substitution remain unreacted.

Amino and other azido of cyclodextrins with moieties containing thermoplastic polymer
The compound derivative can be used for the sheet, film, container or the like of the present invention. A sulfonyl-derived cyclodextrin molecule is converted from a sulfonyl group-substituted cyclodextrin molecule into its amino derivative via a nucleophilic substitution reaction of a sulfonate group with an azide (N ₃ ^-1 ) ion. Can be generated. This azide derivative is substantially modified into a substituted amino compound by reduction. Many of these azide or aminosic dextrin derivatives have been produced. Such derivatives can be prepared by placing a substituted amino group at a symmetric position (these derivatives have two or more amino or azide groups, and those groups are placed on the cyclodextrin backbone at the symmetric positions). The amino or azide-derived cyclodextrin molecule is positioned or substituted in a symmetrical position.For a nucleophilic substitution reaction producing a nitrogen-containing group, the primary hydroxyl group at the carbon atom at position 6 is , Where the nitrogen-containing group is most easily introduced.
For example, acetylamino groups (-NHAc), methylamino, ethylamino, butylamino, isobutylamino, isopropylamino, hexylaminot and the like and alkylamino groups containing other alkylamino substituents. The amino or alkylamino substituent can further react with another compound that reacts with the nitrogen atom to further modify the amino group. Examples of other available nitrogen-containing substituents include dialkylamino, such as dimethylamino, diethylamino, piperidino, piperidinino, quaternary substituted alkyl, or allyl ammonium chloride substituents, halogen derivatives of cyclodextrin, and compatible derivatives. It may be produced as a raw material for producing a substituted cyclodextrin molecule. In such compounds, the primary or secondary hydroxyl groups are replaced by halogen groups such as fluoro, chloro, bromo, iodo, or other substituents. Halogen substitution is most likely to occur at the 6-position primary hydroxyl group.

[0049] Hydrocarbyl-substituted phosphono or hydrocarbyl-substituted phosphato groups may be used to introduce compatible derivatives onto cyclodextrin. The primary hydroxyl group of the cyclodextrin molecule may be replaced by an alkyl phosphato or allyl phosphato group. Secondary hydroxyl groups 2 and 3
Can also be branched using alkyl phosphato groups.

The cyclodextrin molecule can also be substituted with a hanging imidazole group containing a heterocyclic nucleus, a histidine, an imidazole group, a pyridino and a substituted pyridino group. Cyclodextrin derivatives may be modified with sulfur-containing functional groups to introduce compatible substituents on cyclodextrin. In addition to the above sulfonyl acylated groups, sulfhydryl (s
Sulfur-containing groups created according to (ulfhydryl) chemistry may be used. The Such sulfur containing groups, for example, methylthio (-SMe), propylthio (-SPR), t-butylthio _{(-S-C (CH 3)} 3), hydroxyethylthio (-
_{S-CH 2 CH 2 OH)} , imidazolylmethyl thio, phenylthio, substituted phenylthio, include amino alkyl thio and the like. Based on the ether or thioether chemistry described above, a cyclodextrin with a substituted end having hydroxyl aldehyde ketone or carboxylic acid functionality may be provided. Such groups include, for example, hydroxyethyl, 3-hydroxypropyl, methyloxylethyl and the corresponding oxeme isomer,
Hydrocarbyl methoxy _{(-O-CH 2 -CO 2 H} ), hydrocarbyl methoxymethyl ester _{(-O-CH 2 CO 2 -CH} 3)
Is mentioned. Cyclodextrin derivatives containing compatible functional groups may be formed using silicone chemistry.

A cyclodextrin derivative having a silicone-containing functional group may be prepared. A silicone group generally refers to a repeating silicone-oxygen skeleton having a single substituted silicon atom or substituent. Typically, the proportion with certain properties of the silicone atoms in the silicone derivative will have a hydrocarbyl (alkyl or allyl) substituent. Silicone replacement materials typically have increased thermal and oxidative stability and chemical inertness. Moreover, the weather resistance of the silicone group is increased, the dielectric strength is added, and the surface tension is improved. The molecular structure of the silicone group may be modified. Because the silicone group can have one silicon atom or 2 to 20 silicon atoms in the silicone moiety, can be linear or branched, have multiple repeating silicone-oxygen groups, This is because it can be substituted with a functional group. For the purposes of the present invention, a simple silicone-containing substituent desirably comprises trimethylsilyl, a mixed methyl-phenylsilyl group, and the like. We have:
It is known that certain βCD and acetylated and hydroxylalkyl derivatives are available from the corn processing division of American Maize-Products Co., Hammond, Indiana.

(3) Packaging and Packaging Products The thermoplastics containing the compatibility-inducing cyclodextrin are:
It can be used for packaging format for packaging various products. General packaging concepts can be applied. For example, the entire product (item) may be wrapped to form a film pouch or bag. In addition, a film can be used as a fastener for a hard plastic container. The container in that case may have a rectangular, circular, or square cross section, or may have a flat bottom and an open top. Containers and thermoplastic fasteners may be made from the thermoplastic materials of the present invention. In addition, the thermoplastics of the present invention can be used in blister packs, clam shells.
It may be used for mold enclosing tools, bathtubs, trays and the like. Generally, there are two types of products that require packaging with the thermoplastic films of the present invention that have substantial barrier properties. First, it is important to protect the product from contamination from external sources of packaging material. Food products must be protected from various pollutants. The pollutants include, for example, aromatics / aliphatic hydrocarbons, hydrogen fluorides, inks and residues of packaging, transportation and equivalent exhaust gases from internal combustion engines, various consumables (fragrances, etc.). Perfumes commonly used in paper products, bar soap, scented bath products, cleaners, fabric softeners, detergents, dry reach, fungicides, etc.). In most cases, food is the most common substance requiring protection from external contaminants,
There are other products that are sensitive to odors. In many cases, it is necessary to package with a barrier material so that the odor of the object does not leak from the package. Various food smells are easy to pass through various packaging materials. The smell of such foods can attract rats and pests that carry insects and pathogens, causing discomfort to customers and employees, as well as the loss of significant aroma from the packaged product, reducing its commercial value. It could be. Important smells that require a solid barrier include coffee, cooked cereals, frozen pizza, cocoa and other chocolate products, dry mix gravy and soups, snack foods (chips, crackers, popcorn, etc.), baked foods, dry Pet food (cat food, etc.), butter and butter-flavored notes, meat products, especially butter and butter-flavored notes, fruits and nuts used for microwave popcorn in microwaveable paper wrappers is there.

The foregoing has provided a detailed description of the properties of cyclodextrin derivatives, thermoplastic films, the production of films, and a method of producing cyclodextrin to provide compatible derivatives. This provided a basis for understanding such techniques as adding compatible cyclodextrins to thermoplastic films for barrier purposes. In the following examples, the method of producing the film and the penetration data are described to further understand the invention and show the best mode.

Studies on the preparation of cyclodextrin derivatives and synthesis of the cyclodextrin into thermoplastic films have shown that cyclodextrin can be easily derivatized using various well-known chemical protocols. The cyclodextrin material can be easily melt blended with the thermoplastic material, resulting in a cyclodextrin material that is uniformly dispersed in the thermoplastic, resulting in a highly extrudable thermoplastic material. Moreover, we have found that the cyclodextrin derivative can be combined with any and all thermoplastic films. The cyclodextrin material can be added to the film in a wide range of concentrations. The cyclodextrin-containing thermoplastic material is formed into films of various thicknesses by blowing,
It becomes a film or a sheet in a blow-free state without melting tears. Experiments have shown that cyclodextrin derivative technology has reduced the barrier properties, ie, the permeability of aromatic hydrocarbons, aliphatic hydrocarbons, ethanol and water vapor. It has also been found that the surface properties of the film can be improved by using cyclodextrin. The surface tension and surface electrical properties of the film surface were also improved. Thereby, the film of the present invention can be coated, printed,
It has become more practical in fields such as laminating and handling. In an initial study, we also found the following: (1) Some modified cyclodextrins are compatible with LLDPE resins, which reduce the organic permeate dispersed in the film and help improve the synthesis of residual LLDPE volatile contaminants. (2) Unmodified βCD adversely affects the transparency, thermal stability, machinability, and barrier properties of the film. On the other hand, the selected modified βCDs (acetylated and trimethylsilyl ether derivatives) do not affect the transparency and thermal stability. The machinability of the extruded plastics material is such that the surface is marred by some effect, thereby impairing the surface properties of the film. (3) In the film containing the modified βCD component (1% by weight),
35% at 72 ° F. (22 ° C.)
Reduces 38% at 5 ° F (40.5 ° C). Aliphatic permeate was reduced by 9% at 72 ° F (22 ° C). In this experiment,
For the testing of the films, the storage conditions that assumed the worst case were used, but otherwise the results would have improved dramatically. (4) The rate of synthesis differs between aromatic osmotic substances and aliphatic osmotic substances. In the film containing the modified βCD, the compounding ratio of the aromatic substance (gasoline type compound) was higher than that of the aliphatic substance (printing ink type compound). On the other hand, in the film coating, the synthesis results were much better for aliphatic compounds than for aromatic compounds. (5) Acrylic acid film containing βCD has 4
It showed excellent performance in reducing 6% to 88% and aromatics by 29%.

(4) Quality Control First, the present inventors produced four experimental test films. Three of these films contain 1%, 3% and 5% (wt./wt.) Β-cyclodextrin (βCD) in the proportion of extender, while the fourth contains the same resin and additives. Made from a batch of
D was a control film not included. 5% β
For CD films, the synthesis of residual organics in the test films was examined. βCD was found to efficiently synthesize residual organics in linear low density polyethylene (LLDPE) resin, but it was not compatible with the resin and βCD
CD particle agglomerates formed.

The present inventors evaluated nine modified β-cyclodextrins and one ground β-cyclodextrin (particle diameter: 5 to 20 μm). Different cyclodextrin modifications are acetylated, octanyl succinate, ethoxyhexyl glycidyl ether, quaternary amine, tertiary amine, carboxymethyl, succinylated, amphoteric and trimethylsilyl ether. Each experimental cyclodextrin (1% wt / wt) was mixed with low density polyethylene (LLDPE) using a Littleford mixer and using a twin screw Brabender extruder. Extruded.

Nine modified cyclodextrins and one ground cyclodextrin LLDPE profile were obtained at a magnification of 50 ×
And 200 × optical microscope. The results of the microscopic examination were used to visually check the compatibility between the LLDPE resin and the cyclodextrin. Three of the ten cyclodextrin candidates tested (acetylated, octanyl succinate and trimethylsilyl ether) were visually confirmed to be compatible with LLDPE resin.

The synthesized residual film volatiles were 5% C
To test a D film sample and three extruded profiles, cryotrapp
ingprocedure) process. The three profiles contained 1% (wt / wt) acetylated βCD, octanyl succinate βCD, and trimethylsilyl ether. The method consists of three separate steps. The first two are performed simultaneously, and the third is
A technique that helps separate and detect volatile organic compounds, but is performed after the first and second operations. In the first step, an inert, pure dry gas is used to remove volatiles from the sample. During the degassing step, the sample is heated to 120C. The sample was immediately replaced (benzene-d
6). Benzene-d ₆ acts as an internal QC substitute to correct each test data for repair. 2
In the second step, volatiles removed from the sample by freezing the compound are condensed from the removal gas in a headspace bottle impregnated with a liquid nitrogen trap. At the end of the gas removal step, an internal standard (toluene d
8) is poured directly into the headspace bottle and the bottle is immediately capped. The blank of the method and apparatus is supplemented with a sample and processed in the same way as the sample for monitoring contaminants. The condensed organic components are then separated and heated headspace high resolution gas chromatography /
It is qualitatively and quantitatively analyzed by mass spectrometry (HRGC / MS). The results of the analysis of the residual volatile substances are shown in Table 2 below.

[0059]

[Table 2]

In these preliminary screening tests, it was shown that the βCD derivative efficiently synthesizes a small amount of volatile organic substances. Such volatile organics are specific to the low density polyethylene resin used to make the prototype films. In the 5% βCD-extended LLDPE film, nearly 80% of the organic volatiles were synthesized. However, all of the βCD films (1% and 5%) discolored (light brown) and gave off-odors. The problem of color and odor may be due to direct decomposition of CD or impurities contained in CD. Two odorous active compounds (2-furaldehyde and 2-furanmen)
thanol)) is found in the blown film samples.

Among the three modification-compatible CD candidates (acetylated product, octanyl succinate and trimethylsilyl ether), acetylated product and trimethylsilyl ether CD are effective in synthesizing a few volatile organic compounds unique to LLDPE resin. I understood. Increasing the acetylated product and trimethylsilyl ether (TMSE) βCD by 1% resulted in the synthesis of nearly 50% of the residual LDPE organic volatiles, while the residual octanyl succinate was shown not to synthesize with the LLDPE resin volatiles. Crushed βCD
Is 28 compared to acetylated βCD and TMSE-modified βCD.
% Was found to be inefficient.

The plastic packaging materials are all
Interacts to some extent with foods that it protects. The main mode of interaction in plastic food packaging is caused by the movement of organic molecules from the environment through the polymer film into the headspace of the package where they are absorbed by the food. When organic molecules in the package during storage move or pass through the food, not only the temperature and the storage period,
It depends on environmental factors, including factors such as humidity, type of organic molecule and its concentration. Movement is qualitative (sales resistance (con
sumer resistance)) and toxicological effects. The purpose of the packaging film test is that certain barriers
The purpose is to examine how this affects the quality of the packaged foods. To accelerate and simulate the shelf life test for low water activity foodstuffs, the test was run at a temperature of 72 ° F.
(22 ° C), 105 ° F (40.5 ° C) and relative humidity 6
Performed at 0%. These temperature and humidity conditions appear to be similar to those in unregulated warehouses, transportation and storage.

If the polymer is sensitive to humidity, the relative humidity can affect the performance of the film, especially in low water activity foodstuffs. Since the humidity inside and outside the packaging film was extremely different in the actual end use condition, the relative humidity inside the permeation device was controlled on both sides of the film. On the environmental side, outside the package, the relative humidity was kept at 60%, and on the sample side, inside the package containing the low water activity product, 0.25.

A number of osmotic agents were combined and used to examine the function and performance of CD. It is more realistic to combine substances. This is because gasoline (primarily a mixture of aromatic hydrocarbons) and printing ink solvents (primarily,
This is because the mixture of aliphatic hydrocarbons) is not a single compound but a mixture of compounds.

As the aromatic permeable substance, ethanol (20 p
pm), toluene (3 ppm), p-xylene (2 pp
m), o-xylene (1 ppm), trimethyl-benzene (0.5 ppm), and naphthalene (0.5 ppm). Aliphatic penetrants (commercial coating solvent blends containing nearly 20 of various compounds) were 20 ppm.

The penetration test apparatus shown in FIG.
It consists of a glass permeation cell or flask with a cavity of (environment cell or supply side) and 300 nm (sample cell or permeation side).

The performance of the test films was measured in a closed infiltration apparatus. A high resolution gas chromatograph (HRGC) operated by a flame ionization detector (FID) was used to measure the change in cumulative penetrant concentration as a function of time. The compound concentration on the sample side (food side) is calculated from the response factor of each compound. Concentrations are given in parts per million (ppm) based on volume / volume. The cumulative permeate concentration on the sample side of the film is plotted as a function of time.

The present inventors have proposed four experimental test films. Three of them have βCD of 1%, 3%,
And 5% (wt / wt), the fourth film is made from the same batch of resin and additives but does not contain βCD.

A second experimental technique was performed to determine whether the βCD sandwiched between the two control films would synthesize organic vapor that permeated the film. The experiment was performed by gently wiping βCD between the two control films.

As a result of the test, the control film showed β
It was found that the performance was better than that of the CD extended film. The penetration test also showed that the higher the βCD weight gain, the lower the barrier performance of the film. βCD
The results of a test in which was sandwiched between two control films showed that the inclusion of βCD was twice as effective as the control sample without βCD in terms of reducing osmotic vapor. The results of this experiment confirmed that the CD allowed the synthesis of the permeating organic vapors contained in the film, unless the barrier quality of the film impaired its effectiveness as a barrier in the manufacturing process.

The 1% TMSE βCD film is slightly better (24% and 26%) than the 1% acetylated βCD film with respect to the removal of aromatic permeants. 72 ° F (22
° C), no further improvement in quality is observed when denatured CD is further added.

At 105 ° F. (40.5 ° C.) aromatic permeate, both 1% TMSE βCD and 1% acetylated β CD are 13% more than aromatic permeate removal at 72 ° F. (22 ° C.). It will be more efficient soon. The 1% TMSEβCD film still provides the ability to remove aromatic permeants
Slightly better than 1% acetylated βCD film (36%
And 31%).

At 72 ° F. (22 ° C.), 1% TMSEβ
CD is initially more effective at removing aliphatic permeants than 1% acetylated βCD. However, during the test, 1% TMSE βCD was worse than the control film, while 1% acetylated βCD had 6% of the aliphatic permeate.
It only removes%.

We have produced two experimental aqueous coating solutions. One is hydroxyethyl βCD (35% by weight) and the other is hydroxypropyl βCD (35% by weight)
including. In each case, 10 acrylic acid emulsions containing a dispersion of polyacrylic acid emulsion (Polysciences, Inc.) having a molecular weight of about 150,000 (15% by weight solids) as a film-forming additive.
% Included. These solutions were used in performing a handcoat test on a film sample by laminating two LLDPE films together. Two different coating techniques were used. In the first technique, two film samples were stretched very slightly, then coated using a hand roller and laminated while stretching the film flat. The sample of Comparative Example 1 (Rev. 1) was not stretched in the bonding process. All coated samples were ultimately placed on a vacuum lamination press to remove air bubbles between the film sheets. The thickness of the film coating was 0.0005 inches (0.013 mm). These CD coated films and hydroxyl methyl cellulose coated control films were then tested.

The reduction of aromatic and aliphatic vapors by the hydroxyethyl βCD coating was more pronounced during the first few hours of exposure to the vapors, and slowed down over the next 20 hours of the test. The hydroxyethyl βCD coating resulted in higher removal of aliphatic vapors than aromatic vapors. This is believed to be due to differences in molecular size (ie, aliphatic compounds are smaller than aromatic compounds). Over a 20 hour test, aliphatic osmotic substances were reduced by 46% compared to controls. The reduction in aromatics vapor was 29% over the control at the 17 hour test.

Coated hydroxyethyl βCD of Comparative Example 1
Showed a 87% reduction in aliphatic permeate over the 20 hour test compared to the control. A further 41% reduction compared to another hydroxyethyl βCD coated film, but it is not clear whether this is due to the film coating method.

The hydroxyethyl βCD coating is superior to the hydroxypropyl βCD coating in removing aromatic permeable materials at 72 ° F (29% and 20%), albeit slightly.

[0078]

The present invention will be described more specifically with reference to the following examples. 1. Large-scale film experiments (1) Production of cyclodextrin derivatives

[0079]

Example 1 An acetylated hydroxyether β-cyclodextrin having 3.4 acetyl groups per cyclodextrin on the primary -OH group was obtained.

[0080]

Example 2 [Synthesis of trimethylsilyl ether of β-cyclodextrin] 1 minute per minute was placed on a rotary evaporator equipped with a 4000 ml round bottom flask and a nitrogen atmosphere.
00 ml of N ₂ were introduced and 3 liters of dimethylformamide were introduced. To the dimethylformamide was fed 750 grams of β-cyclodextrin. The β-cyclodextrin was rotated and dissolved in dimethylformamide at 60 ° C. After dissolution, the flask was removed from the rotary evaporator and the contents were cooled to near 18 ° C. In the flask, a magnetic stirrer equipped with a stirring bar was installed, and 295 ml of hexamethyldisilirazine was added.
(hexamethyldisilylazine) (HMDS-Pierce Chemical No. 84768) was added and 97 ml of trimethylchlorosilane (TMCS-Pierce Chemical No. 88531) was carefully added.
Was added. When adding trimethylchlorosilane, the operation of carefully dropping 20 ml first and then dropping the next 20 ml after the reaction was completed was repeated until the dropping was completed. After the addition of TMCS was complete and the reaction had subsided, the flask and its contents were placed on a rotary evaporator and the flow of inert nitrogen atmosphere through the rotary evaporator was maintained at 100 ml N ₂ per minute,
Heated to 60 ° C. The solvent was removed after the reaction lasted 4 hours, leaving 308 grams of dry material. The material was removed by sieving the flask and washed with deionized water to remove the silylated product. Vacuum oven drying was performed (75 ° C. at 0.3 inches of Hg (10 kPa)), stored as a powder material, and then left in place until combined with the thermoplastic material. Subsequent observation of the material by spectrophotometric analysis showed that β-cyclodextrin contained trimethylsilyl ether, the ratio of which was close to 1.7 per molecule of β-cyclodextrin. The substitution will usually be on the primary 6-carbon atom.

[0081]

Example 3 Hydroxypropyl β-cyclodextrin having 1.5 hydroxypropyl groups per molecule on the primary 6-OH group of βCD was obtained.

[0082]

Example 4 Hydroxyethyl β with 1.5 hydroxyethyl groups per molecule on the primary 6-OH group of βCD
-Cyclodextrin was obtained. (2) Film formation A series of films were prepared using linear low density polyethylene resin, βCD, and derived βCD such as acetylated β-cyclodextrin or trimethylsilyl derivatives. The polymer particles were dry blended with the powdered β-cyclodextrin or β-cyclodextrin derivative material so that the fluoropolymer lubricant (3M) and the antioxidant were uniformly mixed. The dry blend material is
The blends were extruded into pellets on a Haake device 90, 3/4 "conical extruder. The resulting pellets were collected for formation into a film.

Table 3 shows ordinary pellet extrusion molding conditions. The film was blow molded with the apparatus of FIG.
FIG. 2 shows a state where the thermoplastic tube 21 is extruded from the exit of the die 22. The tube is crushed by a die 23 and turned into a layered film 25 by rollers 24.
The extruded tube 21 is expanded by air under the air pressure blown through the air inlet tube 26. The thermoplastic is melted in the extruder. The temperature of the extruder is measured in the mixing zone 27. The melting temperature is in the melting zone 28 and the die temperature is
Measure with The extruded product is cooled using an air blown cooling flow from the cooling ring 20. The prior art schematic of FIG. 2 is a representative example of a Kiefel blown film extruder with a die diameter of 40 mm,
Used in the production of blown films. Tables 4 and 5 show the films prepared according to the above method. The penetration rate was tested under various environmental conditions. The environmental test conditions are shown in Tables 6 and 7 below.

[0084]

[Table 3]

[0085]

[Table 4]

[0086]

[Table 5]

[0087]

[Table 6]

[0088]

[Table 7]

As a result of the above tests, the addition of the compatible cyclodextrin material of the present invention to the thermoplastic film of the present invention reduces the permeability of various types of permeable materials, thereby substantially reducing barrier properties. improves. Data showing the improvement of the passage rate are shown in the following data tables 8 to 19.

[0090]

[Table 8]

[0091]

[Table 9]

[0092]

[Table 10]

[0093]

[Table 11]

[0094]

[Table 12]

[0095]

[Table 13]

[0096]

[Table 14]

[0097]

[Table 15]

[0098]

[Table 16]

[0099]

[Table 17]

[0100]

[Table 18]

[0101]

[Table 19]

We have determined that hydroxypropyl βCD
A series of aqueous coatings containing was prepared. One of them is a 10% acrylic acid emulsion (purchased from Polysciences Inc., having a molecular weight of about 1).
50,000 polyacrylic acid polymer). The 10% acrylic acid emulsion contains 5% and 10% by weight hydroxypropyl βCD. These solutions were used by laminating two films and laminating a test film sample by hand-coating. The coating was applied to a linear low density polyethylene film sheet containing 0.5% acetylated βCD (roll no. 7) and a second film sheet containing 2% acetylated βCD (roll no. 8). At that time, a film was laminated using a hand roller. The film was not stretched during the lamination operation. All coated samples were placed on a vacuum laminating press to remove air bubbles between the film sheets. The thickness of the acrylic acid coating was about 0.0002 inches (0.0051 mm).
Acrylic acid coated control without hydroxypropyl βCD was prepared in the same manner. The multilayer structure is 0.5% facing the environmental flask side of the test cell.
(See FIG. 3).

The second coating was made from vinylidene chloride latex (PVDC, 60 wt-% solids) purchased from Dagax Laboratories Inc. The PVDC latex coating was made using a derived cyclodextrin containing two levels (10% and 20% by weight) of hydroxypropyl βCD. These solutions were used in laminating two films together and hand-coating a linear low density polyethylene test film sample. The coating was applied to two control film sheets (rolled into one), where they were laminated together using a hand roller. The films did not stretch during the lamination process. All coated samples were placed in a vacuum laminating press to remove air bubbles between the film sheets. The PVDC coating thickness was about 0.0004 inches (0.01 mm). PVDC coated controls were prepared in the same manner, but without hydroxypropyl βCD.

After the preliminary example, data showing the improvement in transmittance will be described. In preparing the data, the following general test method was used. Summary of the Method This method involves an experimental technique devised to measure the permeability of selected organic molecules to food packaging films using a static concentration gradient. The testing methodology is similar to accelerated storage test conditions. That is, the storage humidity and the water activity temperature conditions of the product were variously changed, and the organic concentration examined in the tested food was used so as to be similar to the organic vapor outside the package inside the permeation cell. This method allows for the measurement of compounds such as ethanol, toluene, p-xylene, o-xylene, 1,2,4-trimethylbenzene, naphthalene, naphtha solvent mixtures, and the like. The results are shown in Table 20.

[0105]

[Table 20]

Permeability Test Compound A typical permeability test involves three steps. The three steps are (a) instrument sensitivity calibration, (b) a film test to determine transmissivity and diffusivity, and (c) quality control of the permeation experiment.

Samples of the film are tested in a closed volume permeation apparatus. A high resolution gas chromatograph (HRGC) operated with a flame ionization detector (FID) was used to measure the change in cumulative penetrant concentration as a function of time.

The test compound concentrations on the sample side and the environment side are calculated from the response factors or calibration curves of the respective compounds. If permeation mass is required,
The concentration is then volume corrected for each particular permeation cell.

The cumulative penetrant concentration is shown as a function of time on the upstream (environment) and downstream (sample) side of the film. The diffusion rate and passage rate of the penetrant are calculated from the permeation line data. 1.0 Measuring devices and reagents 1.1 Measuring devices Flame ionization detector
Gas chromatograph (HP 5880) equipped with a 1 ml sampling loop and a 6-port heating sampling valve equipped with a data integrator.

DB-5, 30M X 0.250mm I
D, 1.0 umdf J & W capillary column. Glass penetration test cell or flask. Two glass flasks with cavities of approximately 1200 ml (environment cell or feed side) and 300 ml (sample flask or permeate side) (FIG. 3).

Permeation cell clamping ring (2). Infiltration cell aluminum seal ring (2). Natural rubber diaphragm.
8 mm OD standard wall or 9 mm OD (Aldrich Chemical Company, Milwaukee, Wis.).

Various laboratory glassware and injectors. Various laboratory equipment. 1.2 Reagent Reagent water. Water with no significant chemical analysis MDL impact. A water purifier is used for purifying the reagent water. The water is boiled to 80% by volume before use, capped and cooled to room temperature.

Stock ethanol / aromatic standard solution. 1 ml
Ethanol in a sealed glass ampule (0.6030)
Grams), toluene (0.1722 grams), p-xylene (0.1327 grams), o-xylene (0.06 grams).
66 grams), trimethylbenzene (0.0375 grams) and naphthalene (0.0400 grams) package. The standard for naphtha blends is a commercial paint solvent blend containing about 20 different aliphatic hydrocarbon compounds. It was obtained from Sunnyside Corporation, Consumables Division, Wheeling, Illinois.

Triton X-100. Nonylphenol nonionic surfactant (Rohm and Haas)
ss)). 2.0 Manufacturing Standard 2.1 Working Standard for Permeant The stored permeation test standard solution was used. These criteria are prepared by weighing the formal comparative compound by weight.
Shows actual weight and weight%.

The working standard for ethanol / aromatics is 250
Prepare an injection of μl of the stock standard in 100 ml of reagent water containing 0.1 gram of detergent (Triton X-100). It is important that the Triton X-100 is completely dissolved in the reagent water before adding the osmotic storage standard. This ensures that the test compound disperses in the water. In addition, each time a certain quantity of aliquot is prepared, it must be thoroughly mixed according to working standards. If the measuring flask for preparing the standard solution has a large space, it is wasted. Therefore, in order to minimize the waste, it may be better to transfer the standard solution to a crimp-top bottle having no head space.

In preparing a standard solution of the naphtha mixture, 800 μL of the “neat” naphtha solvent mixture was added to 0.2 g of surfactant (Triton X-100).
And into 100 ml of reagent water.

Unsealed storage standard solutions need to be transferred from glass snap-cap bottles to crimp-top bottles for short-term storage. The bottle may be stored in an explosion-proof refrigerator or freezer.

2.2 Calibration Criteria In preparing the calibration criterion, a fixed volume of working criterion is added to a volumetric flask and diluted with reagent water to set at least three concentration levels. One of the criteria is a concentration slightly above the detection limit. Other concentrations correspond to the environmental and expected detected concentrations of the sample side cell. 3.0 Sample Preparation 3.1 Film Sample Preparation The environment flask and sample flask of FIG. 3 are washed with soapy water before use, rinsed thoroughly with deionized water, and dried in an oven. Following washing, a rubber septum is placed on each flask.

[0119] The film test sample is cut with a template according to the inner diameter of the aluminum seal ring. The diameter of the film test sample is important in preventing diffusion loss around the cut edge. The film sample, aluminum seal and flask are assembled as shown in FIG. 3, but the clamping ring nut is not tightened.

A test cell shown in FIG. 3 is prepared. First, the sample flask 32 and the environmental flask 31 are flushed with dry compressed air to remove moisture in the sample and the environmental flask. At this time, the sample device 33 and the environmental diaphragm 34 are pierced with a needle, and a tube is attached to the assembly for the purpose of controlling the flow of dry air flowing simultaneously to both flasks. Clamp ring 35 is loosely fastened to the flask, thereby reducing the pressure on either side of film 30. After flushing both flasks with air for about 10 minutes, remove the needle and tighten the clamp ring to seal the film 30 between the two flasks. Aluminum spacers 36a and 36b having rubber adhered to the front surface are used to reliably enclose the gas.

On the sample side, 2 μL of water is injected per 300 ml of flask volume. As the volume of the sample flask changes, the amount of water changes as the volume changes. 2 μL water per 300 ml flask volume
This corresponds to a product having a water activity of 0.25 at 73 ° F.
Next, 40 μL of osmotic ethanol / aromatics working criteria or naphtha blend standard solution prepared according to section 2.2 is injected into the environmental flask. For all of these standard solutions, the osmotic agent concentration (1 million volumes / volume per part) in the 1200 ml volumetric flask of Table I
The relative humidity is 60% at 72 ° F (22 ° C). Other humidity and osmotic substance concentrations are employed in a humidity chart for determining humidity and in a test method for calculating osmotic substance concentrations using gas loss. Record the time and place the infiltration cell in a temperature controlled oven. The sample is shifted according to the GC operation time. Prepare three infiltration devices in each case. Perform quality control by performing triple analysis.

At regular intervals, a group sample is removed from the oven. First, an environmental flask is analyzed using a heated 6-neck sampling valve closed with a 1 ml loop. The loop is flushed with 1 ml of environmental or sample side air. The loop is injected onto a capillary column. After injection, start the GC / FID device manually. 1m from the sample of one infiltration experiment and the environment side
1 sample injection is performed up to 8 times.

Test compound concentration on sample side and environment side
Is calculated from the calibration curve or response factor of each compound.
(Equation 1 or 3). Where infiltration mass is required
Then, for each specific set of infiltration flasks
Adjust the volume of the solution accordingly. 4.0 Sample analysis 4.1 Instrument parameters The standards and samples were prepared using the following method parameters:
And analyzed by gas chromatography.

Column: J & W column, DB-5, 30
M, 0.25 mm ID, 1 umdf Carrier: hydrogen Split vent: 9.4 ml / min Inlet temperature: 105 ° C Flame detector temperature: 200 ° C Oven temperature 1: 75 ° C Program speed 1: 15 ° C Oven Temperature 2: 125 ° C. Program speed 2: 20 ° C. Final oven temperature: 200 ° C. Final holding time: 2 minutes 6 ports The sampling valve temperature is set to 105 ° C.

4.2 Calibration Within the range of test compounds shown in Table 21 below, three calibrations are made using criteria.

[0126]

[Table 21]

For the purpose of preparing a calibration standard, an appropriate amount of the working standard solution was added to a partial standard solution (aliqu
ot). 4.2.1 Second dilution of standard solution for calibration curve 5: 1 dilution: 5 ml of the standard solution is placed in a 25 ml volumetric flask, stoppered, and the flask is inverted to mix.

2.5 to 1 dilution: 10 ml working standard
Place in a 5 ml volumetric flask, stopper and mix by inverting the flask. Each of the calibration standards is analyzed, and a comparison between the detection area of the compound peak and the concentration of the test compound in the environmental cell is summarized in a table. The result is used for preparing a calibration curve for each compound. The naphtha solvent mixture contains 20
It is a commercially available paint solvent with various aliphatic hydrocarbon compounds nearby. The ratio of response to concentration is determined by the sum of the areas under each of the 20 peaks. By the least squares method,
Fit the straight line to the calibration curve. Thereafter, the slope of the calibration curve of each compound is calculated to determine the unknown concentration. An average response factor may be used instead of the calibration curve.

An action calibration curve or response factor must be measured on one or more calibration standards and checked on each working day. Response changes of all compounds were 20
If the percentage is exceeded, the test must be repeated using the new calibration standards. If the results still do not match, a new calibration curve needs to be created.

4.3 Analysis of Calibration Curve and Detection Method Standard samples Desirable chromatography conditions have been described above.

The device is weighed daily as described above. Check and adjust split vent traits. In checking, a soap film flow meter is used.

To generate accurate data, samples, calibration standards, and method detection level samples must be analyzed under identical conditions. Samples for calibration standards and detection methods are formed only in environmental flasks. In this case, instead of the sample flask, a 1 / 2-inch plastic disc and an aluminum sheet disc that match the diameter of the environmental flange are used. One sealing ring is placed on the environmental glass flange, on which the aluminum sheet and plastic disc are placed.

The environmental flask is flushed with dry compressed air to remove moisture in the sample and the environmental flask. In doing so, a needle is pierced into the environmental septum and a tube is attached to the assembly that allows for regulation of the flow of dry air through the flask. The clamp ring is loosely fastened to the flask, thereby suppressing the pressure increase. After flushing both flasks with air for about 10 minutes, the needle is removed and the clamp ring is tightened, sealing the aluminum sheet to the seal ring.

Next, 40 μL of osmotic ethanol / aromatic action standard or a second dilution of the action standard is injected into the environmental flask. Alternatively, inject 40 μL of a second dilution of the naphtha solvent blend or standard solution into the environmental flask. Record the time and place the flask in a temperature controlled oven.

Every 30 minutes, an environmental sample is removed from the oven. Heat 6 combined with 1 ml loop
The environmental flask is analyzed using a mouth sampling valve. The loop is flushed with a 1 ml volume of environmental or sample side air. The loop is injected onto a capillary column. After injection, start the GC / FID device manually. 4.4 Calculation of Results 4.4.1 Test Compound Detection Factor The test compound concentration on the sample side and the environmental side is calculated from the calibration curve slope or the response factor (RF) of each compound. If you need the mass of the permeable material, then
Volume adjust the concentration for each particular set of permeation cells.

Compound concentration (ppm) = Peak area / Calibration curve gradient (1) Compound identification RF = Compound concentration (ppm) / Peak area (2) Compound concentration (ppm) = Peak area × RF (3) Cumulative The penetrant mass is shown as a function of time on the upstream (environment) and downstream (sample) side of the film. The diffusion rate and the transmissivity of the permeation area are calculated from transmission line data.

4.4.2 Permeability When the permeable material does not interact with the polymer, the permeability coefficient R is usually specific to the permeable material-polymer device. In this case, many gases such as hydrogen, nitrogen, oxygen, carbon dioxide penetrate many polymers. If the penetrant interacts with the polymer, such as the penetrant test compound used in this method, P will not be constant and will depend on pressure, film thickness, and other conditions. Will be done. In such a case, the value of P alone does not represent the permeability inherent in the polymer film, but to obtain an overall distribution of the permeability of the polymer, the dependence of P on the variables as conceivable is needed. You need to know the degree. In these cases, if the saturation vapor pressure of the permeable material at a particular temperature is applied to the entire film, the transmittance Q is often used in effect. The permeability of a film to water and organic compounds is often expressed by the following method.

P = [(amount of permeable material) (film thickness)] / [(area) (time) (pressure drop over the entire film)] (4) Q = [(amount of permeable material) (film thickness) Sa)] / [(area) (time)] (5) In this application example, Q is represented by the following equation (Equation 1).

[0139]

(Equation 1)

One of the main variables in determining the permeability coefficient is the pressure drop across the film. Transmittance Q
Does not include osmotic agent concentration or pressure.
Therefore, in order to show the correlation between Q and P, it is necessary to know the vapor pressure or the permeable substance concentration under the measurement conditions.

The pressure drop across the film from the environment side to the sample side is mainly due to the water vapor pressure. Since the water concentration and humidity are not constant and are not measured each time an organic compound is analyzed, the pressure applied to the entire thin film is not determined.

The examples of thermoplastic films containing the various compatible cyclodextrin derivatives given above show that the present invention can be practiced with a variety of different thermoplastic films. Moreover, various types of compatibility-derived cyclodextrin materials may be used in the present invention. That is, the film of the present invention can be manufactured using various film manufacturing techniques. Such techniques include:
Examples include extrusion and aqueous dispersion coatings to form useful barriers.

The above description, examples of substituted cyclodextrins, extruded thermoplastic films and test data will assist in the technical understanding of the present invention.

[0144]

As described above, the present invention has excellent barrier properties and is compatible (compatible) when mixed with other resins.
The present invention can provide a food packaging film and a packaged food containing a cyclodextrin derivative, which does not significantly reduce transparency, processability, or structural characteristics.

[Brief description of the drawings]

FIG. 1 shows the size of a cyclodextrin molecule without induction. The α, β, and γ dextrins are shown.

FIG. 2 is a schematic diagram of an extruder used to form the films shown in Table 1.

FIG. 3 shows a test device used in examining the permeability of the film of the present invention.

[Explanation of symbols]

 Reference Signs List 20 cooling ring 21 tube 22 die 23 annular die 24 roller 25 film 26 air inlet 27 mixing zone 28 melting zone 29 extrusion unit 30 film 31 environmental flask 32 sample flask 33 sample device 34 environmental diaphragm 35 clamp ring 36a, 36b aluminum spacer

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-62-263047 (JP, A) JP-A-3-167261 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) C08L 1/00-101/14 C08J 5/18

Claims (15)

(57) [Claims] 1. A food packaging film comprising a thermoplastic film composition having improved barrier properties,
(A) a thermoplastic polymer; and (b) a polymer-compatible cyclodextrin derivative that is uniformly dispersed in the polymer and effectively absorbs the penetrant, wherein the cyclodextrin is substantially free of mixed complex compounds. A food packaging film which is a thermoplastic film composition. 2. The food packaging film according to claim 1, wherein the permeable substance includes a residual polymer volatile substance. 3. The food packaging film according to claim 1, wherein the food is a liquid food. 4. The film for food packaging according to claim 1, wherein the thermoplastic polymer is a chlorine-containing vinyl polymer containing vinyl chloride or vinylidene dichloride. 5. The method of claim 1, wherein the thermoplastic polymer is poly (vinyl chloride-co-vinyl acetate) or poly (vinyl chloride-co-vinylidene dichloride).
A food packaging film according to claim 1. 6. The food packaging film according to claim 1, wherein the thermoplastic polymer is polyvinyl alcohol, poly (ethylene-co-vinyl alcohol), or poly (ethylene-co-methyl acrylate). 7. The food packaging film according to claim 1, wherein the cyclodextrin derivative includes a β-cyclodextrin derivative. 8. The food packaging film according to claim 1, wherein the cyclodextrin derivative has at least one substituent on a cyclodextrin primary carbon atom. 9. The food packaging film according to claim 1, wherein the cyclodextrin is α-cyclodextrin, β-cyclodextrin, γ-cyclodextrin, or a mixture thereof. 10. The food packaging film according to claim 1, wherein the thermoplastic polymer comprises 0.1 to 5% by weight of a polymer compatible cyclodextrin derivative. 11. The food packaging film according to claim 1, wherein the thermoplastic polymer is a polyester. 12. The method according to claim 12, wherein the polyester is poly (ethylene-co-
The food packaging film according to claim 11, which comprises (terephthalate). 13. The food packaging film according to claim 1, wherein the thermoplastic polymer is polyethylene. 14. The food packaging film according to claim 13, wherein the polyethylene is a high-density polyethylene. 15. A packaged food packaged with the food packaging film according to any one of claims 1 to 14.