JP2010096738A - Evaluating method on permeability of chemicals for polymer film - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method that readily evaluates the permeability of chemicals for polymer film. <P>SOLUTION: The characteristics of the evaluating method on the permeability of chemicals for polymer film is as follows; after bring chemicals into contact with one side surface of a polymer film, the total-reflection absorption spectra containing inherent absorbing wavenumber of the chemicals concerned is measured by means of a Fourier-transform infrared spectrophotometer on the opposite side surface to that with which the chemicals concerned is brought into contact to evaluate the permeability of the chemicals concerned on the polymer film concerned. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a method for evaluating chemical permeability of a polymer film.

Bags that wrap all kinds of goods such as food and drinks, pharmaceuticals, and daily miscellaneous goods are laminated on a base film with several types of layers with various properties such as strength, light-shielding properties, barrier properties, and sealing properties. It is obtained by making a polymer film) into a bag shape. These laminated films have a sealant layer on the inner surface, and are processed into a bag shape having an opening by thermocompression bonding (heat sealing) the sealant layers together by heat in a bag making process. In order to impart properties such as strength, light-shielding properties, and barrier properties depending on the packaging application, a multilayer film having properties on the outside of the sealant layer is laminated using an adhesive.
As the adhesive, a mixture mainly composed of polyurethane resin, polyester resin, polyether resin or the like is generally used. These contain low molecular weight ester compounds, and if these components penetrate the sealant layer of the inner layer that is in contact with the adhesive layer, adverse effects on the packaged article become a problem. For example, when the content is a food or drink, these components may cause a strange odor or taste, and when the content is an electronic component, it may cause contamination or corrosion. .

  In addition, these laminated films may be subjected to heat treatment for the purpose of curing the adhesive, etc., and there is a concern that this heat treatment promotes permeation of the low molecular weight ester compound in the sealant layer of the inner layer of the laminated film. Is done.

  Furthermore, in order to impart functionality to the laminated film, additives such as an antioxidant, a lubricant, an antiblocking agent, and an antistatic agent may be added to each layer.

  For example, the lubricant imparts slipperiness to the film by allowing a part of the added lubricant to permeate the sealant layer which is a polymer film which is the innermost layer and bleed out to the surface of the sealant layer. Bleed-out means that a substance in the inner layer, for example, a lubricant, moves from the inner layer through a fine hole and moves to the surface layer and precipitates. The same applies to the movement from the surface layer to the inner layer.

  The laminated film used for packaging has a sealant layer (polymer film) on the inner surface, and the sealant layers are thermocompression-bonded (heat-sealed) with heat in a bag making process to be processed into a bag shape having an opening. And the processed product processed into the bag shape is filled with the contents from the opening in the filling process, and further, the contents are sealed by thermocompression bonding (sealing) the sealant layers of the opening, and shipped as a product. Is done. At this time, among the additives added to the laminated film, the lubricant is added to give the film slipperiness. If the slipperiness of the film is not appropriate, problems may occur in a bag making process for processing a laminated film into a bag shape or a content filling process for filling a processed product processed into a bag shape.

  That is, if there is a variation in the amount of lubricant on the surface of the sealant layer, a variation in the feed amount of the laminated film will occur in the bag making process, resulting in problems such as a shift in the seal width and a shift in the printed pattern. Moreover, the laminated film used for packaging is processed into a bag shape in the processing step, and the processed product is in contact with the sealant layers. In filling the bag-like workpiece with the contents in the filling step, it is necessary to open the opening of the bag-like workpiece.

  At this time, it is necessary that a sufficient amount of the lubricant necessary for providing the slipperiness to easily peel off the contacted sealant layer has moved (bleeded out) to the surface of the sealant layer which is the innermost surface layer. There is.

  In this way, a part of the lubricant added to the laminated film permeates the sealant layer, which is a polymer film that is the innermost surface layer, and bleeds out to the surface of the sealant layer. After laminating a multilayer film having appropriate transmission characteristics on the outside using an adhesive, the laminated film is subjected to heat treatment for the purpose of curing the adhesive or the like.

  At this time, there is a possibility that the lubricant that bleeds out to the surface of the sealant layer of the innermost layer of the laminated film by this heat treatment moves the sealant layer and permeates to the adhesive layer side (Patent Document 1). Therefore, there is a concern that after the heat treatment is completed, the lubricant is held in the adhesive layer or the laminated film of the outer layer, and the amount of bleed out again on the surface of the sealant layer of the lubricant is reduced.

JP-A-11-334004 JP 2001-272390 A JP 2006-343263 A

  As a method for evaluating chemical permeability of a film, for example, a gas chromatographic method (GC method) has been conventionally known. However, as a chemical to be evaluated, it is limited to a compound that easily volatilizes (Patent Document 2). .

  However, since these fatty acid amides or alkylene bis fatty acid amides are hardly volatile compounds, for example, methylene bis-stearic acid amide is difficult to evaluate by gas chromatography, and many other fatty acid amides use gas chromatography. In some cases, it is necessary to perform pretreatment such as extraction with a solvent, and it is necessary to examine the extraction solvent, extraction efficiency, and the like according to the chemicals to be evaluated.

  That is, in order to evaluate the chemical permeability of a polymer film using the gas chromatographic method, in addition to having the knowledge necessary for judging the measurement conditions, etc., experience and skill for operation are required. However, the situation was not convenient.

  As a method for evaluating chemical permeability of a film, a method of measuring a diffusion coefficient of a chemical in a polymer film is known.

  As a typical method, for example, a method of measuring a cutting surface in a cross-sectional direction of a polymer film is known. In this method, a device for creating a cutting surface and a specialist for an operation for creating the cutting surface are known. Skill and skill are required. Moreover, since the diffusion coefficient calculated | required by this method is estimated with the depth which the chemical | medical agent permeate | transmitted, when the film is a laminated structure, since the transmission | permeation of a chemical | medical agent differs, possibility that a permeability cannot be evaluated correctly is considered ( Patent Document 3).

  As described above, there is not always a method for appropriately and simply evaluating the chemical permeability of a film. In the present invention, the chemical permeability of a polymer film is simply evaluated. It is an object to provide a method.

  The invention according to claim 1 for solving the above-mentioned problem is a method for evaluating chemical permeability of a polymer film, wherein after the chemical is brought into contact with one side of the polymer film, the surface of the polymer film is By measuring the total reflection absorption spectrum including the intrinsic absorption wave number of the chemical with a Fourier transform infrared spectrophotometer on the surface opposite to the surface in contact with the chemical, the permeability of the chemical in the polymer film is measured. It is a method for evaluating chemical permeability of a polymer film, characterized by being evaluated.

The invention according to claim 2, wherein the drug is an ester compound, a polymer film of claim 1, wherein the specific absorption wave to the ester compound is characterized by a range of 1750cm ^-1 ~1710cm ^-1 It is a chemical permeability evaluation method.

The invention according to claim 3, wherein the drug is a fatty acid amide or alkylene bis fatty acid amide, that specific absorption wave to the fatty acid amide or the alkylene bis fatty acid amide is in the range of both ^{1680cm -1 ~1610cm} -1 The method for evaluating chemical permeability of a polymer film according to claim 1.

  The invention according to claim 4 is the method for evaluating chemical permeability of the polymer film according to claim 3, wherein the polymer film is a thermal transfer ink sheet.

  By using the chemical permeability evaluation method of the polymer film of the present invention, the chemical permeability of the polymer film could be easily evaluated.

  Furthermore, it is possible to provide a method for simply evaluating the permeability of the ester compound as a polymer in a polymer film.

  In addition, it is possible to provide a method for simply evaluating the permeability of a polymer film of fatty acid amide or alkylene bis fatty acid amide as the chemical.

  Furthermore, it is possible to provide a method for simply evaluating chemical permeability when a thermal transfer ink sheet is used as the polymer film.

FIG. 1 is an explanatory view of a method for evaluating chemical permeability of a polymer film of the present invention.

  The present inventor tackled the above-mentioned problem, and as a result of earnest examination, after bringing a chemical into contact with one side of the polymer film, the amount of the chemical is quantified on the opposite side of the surface of the polymer film where the chemical is brought into contact. It was found that the chemical permeability of the polymer film can be easily evaluated. Furthermore, as a method for quantifying the drug present on the surface of the polymer film, the total reflection absorption (ATR) spectrum including the absorption wave number specific to the drug is obtained using a Fourier transform infrared spectrophotometer (FT-IR). We found that it can be quantified by measuring.

  FIG. 1 shows an explanatory view of a method for evaluating chemical permeability of the polymer film of the present invention. In the evaluation method of the present invention, the chemical 2 to be evaluated is brought into contact with one surface X of the polymer film 1 (FIGS. 1A and 1B). Next, the total reflection absorption (ATR) including the absorption wave number peculiar to a chemical | medical agent using the Fourier-transform infrared spectrophotometer (FT-IR) about the surface Y on the opposite side to the surface X which the chemical | medical agent of the polymer film 1 contacted. ) The spectrum is measured (FIG. 1 (c)). As described above, the evaluation method of the present invention is performed, and the chemical permeability of the polymer film can be simply evaluated from the absorption intensity of the absorption wave number inherent to the chemical.

The present invention is described in detail below.
When the chemical to be evaluated is solid at the evaluation temperature, it is preferable to dissolve the chemical with a solvent. Even when the chemical is liquid at the evaluation temperature, it is preferably dissolved in a solvent. Dissolving with a solvent facilitates uniform dispersion of the chemical.

  The solvent is preferably a solvent that dissolves chemicals, and more preferably liquid at room temperature. Moreover, it is preferable that it is a solvent which does not have absorption in the infrared absorption wave number area | region intrinsic | native to the chemical | medical agent of evaluation object. For example, when the chemical to be evaluated is an ester compound, water, ethylene glycol, polyethylene glycol, polyethylene wax, chloroform, silicone, hexane, toluene, methanol, ethanol, isopropyl alcohol, or the like can be preferably used. When the evaluation object is a fatty acid amide or an alkylene bis fatty acid amide, chloroform, tetrahydrofuran or the like can be suitably used.

  It is preferable that the polymer film and the chemical to be evaluated be kept in contact with each other for a certain period of time. At this time, the chemical to be evaluated and the polymer film may be heated.

  In bringing the evaluation target chemical into contact with the polymer film, it is preferable to keep the contact area between the evaluation target chemical or the solvent in which the evaluation target chemical is dissolved and the polymer film constant. Therefore, it is more preferable to impregnate a certain amount of a chemical to be evaluated or a solvent in which the chemical to be evaluated is dissolved into a filter paper or a cloth having a certain area and affix it to the polymer film. In addition, by impregnating a chemical with filter paper or cloth, it is possible to easily bring a certain amount of chemical into contact with a polymer film having a certain area.

  In addition, when a certain amount of the chemical to be evaluated or a solvent in which the chemical to be evaluated is impregnated is impregnated into a filter paper or a cloth with a certain area, and affixed to the polymer film, an O-ring is placed around the filter paper or cloth attached with the polymer film. It is preferable to fix the polymer film so that it does not come into contact with the rubber-like rubber and metal or glass.

  Depending on the evaluation conditions, the polymer film may be twisted even if it is fixed around the filter paper or cloth attached with the polymer film with an O-ring rubber and metal or glass. .

  When heating the polymer film in contact with chemicals or when the polymer film is thin, use a plate with a smooth surface, and use a plate with a smooth surface to remove the chemical to be evaluated or the solvent in which the chemical to be evaluated is dissolved between the polymer film and the plate. It is preferable to apply to the surface using surface tension.

  In that case, it is preferable that the plate to be used is not deformed at the evaluation temperature, and the chemical to be evaluated and the solvent used for the evaluation do not penetrate and are not corroded, for example, a glass plate, a silicon wafer, a stainless steel plate, a gold-plated plate, etc. is there.

  Further, in order to suppress the evaporation of the chemical and the solvent used, it is preferable to leave the contact surface of the polymer film and the chemical covered with a sealed container. When heating in a state where the polymer film is in contact with the chemical, it is necessary to pay sufficient attention to the characteristics such as the boiling point and ignition point of the chemical and the solvent from the viewpoint of safety.

  Examples of the polymer film include polyolefin resins such as polyethylene and polypropylene, or copolymers having polyethylene or polypropylene as a constituent, for example, linear low density polyethylene, low density polyethylene, medium density polyethylene, high density polyethylene, polypropylene. , Ethylene-vinyl acetate copolymer, ethylene-acrylic acid copolymer, ethylene-methyl acrylate copolymer, ethylene-propylene copolymer, ethylene-cycloolefin copolymer, etc. Examples of such a resin include films and sheets laminated in a single layer or a multilayer structure of two or more layers. The polymer film of the present invention includes not only a film shape but also a sheet shape.

An ester compound is preferably used as the chemical to be evaluated in the present invention. Ester compounds specific absorption wave numbers from ester bonds is in the range of ^{1750cm -1 ~1710cm} -1. By measuring the absorption intensity of a peak in ^{1750cm -1 ~1710cm} -1 from the ester bond, it is possible to evaluate the drug permeability of the polymeric film.

  The ester compound used as the chemical of the present invention is used as an impurity contained in the adhesive and coating agent fields, and as a plasticizer, and it is important to evaluate the permeability of the ester compound in the polymer film. Specific examples of the ester compound to be evaluated include isobutyl acrylate, isobutyl propionate, butyl isobutyrate, dimethyl sebacate, and dimethyl azelate.

In addition, fatty acid amides or alkylene bis fatty acid amides can be used as chemicals to be evaluated in the present invention. Fatty acid amide or alkylene bis fatty acid amide intrinsic absorption wavelength of from amide bond is in the range of ^{1680cm -1 ~1610cm} -1. By the origin the amide bond of measuring the absorption intensity of a peak in ^{1680cm -1 ~1610cm} -1, it is possible to evaluate the drug permeability of the polymeric film.

  Fatty acid amides or alkylene bis fatty acid amides are used as lubricants and waxes on the film surface, for example, in the field of thermal transfer ink sheets and packaging materials.

  Thermal transfer ink sheets are used in thermal transfer printers, etc., and the ink layer is selectively heated by a recording head such as a thermal head from the back side of the sheet coated with hot melt ink on a film onto a transfer medium such as paper. It is transferred to form letters, designs, photographs, etc.

  The thermal transfer sheet is obtained by forming a layer made of hot melt ink on a base made of polymer. A hot melt ink requires a high pigment content in order to print with high accuracy and sufficient density, and therefore a wax component having a pigment dispersion function is added. In addition, there are a solvent application method and a melt application method as the application method of such hot melt ink, and among these, the melt application method is a method of applying the hot melt ink in a molten state, and exhibits good applicability. For this purpose, a wax component having an appropriate melting point is added to the hot-melt ink. The thermal transfer ink sheet is heat-treated when the hot-melt ink is melt-coated. At this time, fatty acid amide or alkylene bis fatty acid amide is used as the wax.

  Here, when the thermal transfer ink sheet is heated, there is a possibility that the wax component added to the hot melt ink by the heat treatment moves in the sheet and reaches the back surface of the sheet. The back surface of the sheet is subjected to a slip control process such as a back coat layer in order to properly control the feeding of the thermal transfer ink sheet when printing with a thermal transfer printer. When the wax component reaches the back surface, a problem may occur in this slipping property. Therefore, it is important to evaluate the chemical permeability of fatty acid amide or alkylene bis fatty acid amide which is a wax component in the thermal transfer ink sheet.

  The gas chromatographic method (GC method) is limited to compounds that are likely to volatilize as chemicals to be evaluated, and it is difficult to evaluate fatty acid amides or alkylene bis fatty acid amides on polymer films. In the chemical permeability of the polymer film of the present invention, the total reflection absorption spectrum including the intrinsic absorption wave number of the chemical is measured by a Fourier transform infrared spectrophotometer, whereby the fatty acid amide or alkylene bis on the molecular film is measured. Fatty acid amides and the like could be evaluated.

  As the fatty acid amide to be evaluated, for example, stearic acid amide, oleic acid amide, erucic acid amide, behenic acid amide and the like can be used. Further, as the alkylene bis fatty acid amide to be evaluated, methylene bis stearic acid amide, ethylene bis stearic acid amide, ethylene bisolefinic acid amide and the like can be used. These are used as lubricants for packaging materials and the wax component of thermal transfer ink sheets as described above.

  Although the specific Example of this invention is described below, this invention is not limited to this.

<Example 1>
First, as a cyclic olefin polymer, a copolymer containing 30% by weight of tetracyclododecene and 70% by weight of ethylene was used to obtain a coextruded polymer film having a two-layer structure of a cyclic olefin polymer layer and a low density polyethylene layer.

  At this time, three types of polymer films having a two-layer structure were produced as the polymer film. Specifically, a cyclic olefin polymer layer 20 μm thick / low density polyethylene layer 80 μm thick polymer film, a cyclic olefin polymer 5 μm thickness / low density polyethylene layer 80 μm thick polymer film, a cyclic olefin polymer 1 μm thickness / low density polyethylene layer A polymer film having a thickness of 80 μm was prepared. In addition, one kind of single-layer polymer film was prepared. Specifically, a 100 μm thick polymer film of low density polyethylene was prepared. A total of four types of polymer films were evaluated.

  First, after placing the low-density polyethylene surface of the polymer film on the stainless steel plate so as to be in contact with the stainless steel plate, the film was fixed using an O-ring of silicon rubber and an O-ring made of stainless steel.

  Next, after applying 10% by weight of a solution dissolved in polyethylene glycol having an average molecular weight of 200 to the surface not in contact with the stainless steel plate, the glass plate is placed and propionic acid is used between the film and the glass plate using surface tension. The isobutyl solution was fixed.

  They were sealed in glass containers and stored in an oven at a temperature of 50 ° C. for 48 hours.

After removing the isobutyl propionate solution on the surface not in contact with the stainless steel plate, the total reflection absorption (ATR) spectrum of the surface in contact with the stainless steel plate was measured using a Fourier transform infrared spectrophotometer (FT-IR). Measured and determined the absorption intensity derived from isobutyl propionate near 1730 cm ⁻¹ .

When the absorption area derived from isobutyl propionate near 1730 cm ⁻¹ is A and the absorption area derived from low density polyethylene near 1470 cm ⁻¹ is B, the absorption intensity derived from isobutyl propionate is A / B. did.

  The results are shown in Table 1. As shown in Table 1, as an example of a method for evaluating the chemical permeability of a polymer film, the chemical permeability of the ester compound as a chemical to the polymer film could be easily evaluated.

<Example 2>
Using a copolymer containing 30% by weight of tetracyclododecene and 70% by weight of ethylene as a cyclic olefin polymer, a co-extruded polymer film having a three-layer structure of a low density polyethylene layer, a cyclic olefin polymer layer, and a low density polyethylene layer is obtained. It was.

  At this time, three types of polymer films having a three-layer structure were prepared as samples. Specifically, low density polyethylene 40 μm thick / cyclic olefin polymer layer 20 μm thick / low density polyethylene layer 40 μm thick polymer film, low density polyethylene 40 μm thick / cyclic olefin polymer 5 μm thick / low density polyethylene layer 40 μm thick A molecular film and a polymer film having a low density polyethylene of 40 μm thickness / a cyclic olefin polymer of 1 μm thickness / a low density polyethylene layer of 40 μm thickness were prepared.

  Furthermore, one type of single-layer polymer film was prepared as a polymer film. It is a polymer film with a thickness of 100 μm. These four types of polymer films were evaluated.

  First, after placing this polymer film on a stainless steel plate, the film was fixed using an O-ring made of silicon rubber and an O-ring made of stainless steel.

  Next, after applying a 1% by weight solution of erucamide dissolved in chloroform to the surface not in contact with the stainless steel plate, a glass plate (preparation) is placed on the surface, and erucic acid is used between the film and the glass plate using surface tension. The amide solution was fixed.

  After standing for a while and confirming that chloroform has been volatilized, sealed with a glass container, heated in an oven at a temperature of 80 ° C. for 6 hours, and further stored in an oven at a temperature of 50 ° C. for 48 hours. And stored in an environment at a temperature of 23 ° C. and a humidity of 60% for 72 hours.

After removing erucamide on the surface not in contact with the stainless steel plate, the total reflection absorption (ATR) spectrum of the surface in contact with the stainless steel plate is measured using a Fourier transform infrared spectrophotometer (FT-IR). The absorption intensity derived from erucic acid amide near 1650 cm ⁻¹ was determined.

  The results are shown in Table 2. As shown in Table 2, as an example of a method for evaluating chemical permeability of a polymer film, the chemical permeability of a fatty acid amide polymer film as a chemical could be easily evaluated.

DESCRIPTION OF SYMBOLS 1 Polymer film 2 Chemical | medical agent (evaluation object) X One surface of a polymer film Y The surface on the opposite side to X of a polymer film 3 Infrared light (incident light)
4 Infrared light (reflected light)

Claims (4)

  A method for evaluating chemical permeability of a polymer film, wherein a chemical is brought into contact with one side of the polymer film, and then a surface of the polymer film surface opposite to the side in which the chemical is brought into contact is subjected to Fourier transform infrared. Evaluation of drug permeability of a polymer film characterized by evaluating the permeability of the drug in the polymer film by measuring a total reflection absorption spectrum including the intrinsic absorption wave number of the drug with a spectrophotometer Method. The drug is an ester compound, according to claim 1 chemicals permeability evaluation method of a polymer film, wherein the specific absorption wave to the ester compound is in a range of 1750cm ^-1 ~1710cm ^-1. The drug is a fatty acid amide or alkylene bis fatty acid amides, higher of claim 1, wherein the specific absorption wave in the fatty acid amide or the alkylene bis fatty acid amide is in the range of 1680cm ^-1 ~1610cm ^-1 Evaluation method of chemical permeability of molecular film.   The method for evaluating chemical permeability of a polymer film according to claim 3, wherein the polymer film is a thermal transfer ink sheet.

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