JP2008049605A - Transparent laminate having retort suitability - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a transparent laminate imparted with retort suitability for packaging fields requiring high gas-barrier performance and retort processing, e.g. food, non-food and drug industries. <P>SOLUTION: The transparent laminate is provided with the retort aptitude of a substrate consisting of a transparent plastic film. It is formed by pretreating one or both sides of the substrate consisting of the transparent plastic film through reactive ion etching (RIE) with plasma and laminating, in order, a vapor-deposited thin-film layer composed of an inorganic oxide on the plasma-pretreated surface and a gas-barrier coating layer formed by applying a solution containing one or more selected from silicon compounds of formula Si(OR<SP>1</SP>)<SB>4</SB>and/or R<SP>2</SP>Si(OR<SP>3</SP>)<SB>3</SB>(wherein R<SP>1</SP>and R<SP>3</SP>are hydrolyzable groups of C<SB>n</SB>H<SB>2n+1</SB>, C<SB>m</SB>H<SB>2m</SB>, OC<SB>e</SB>H<SB>2l+1</SB>; and R<SP>2</SP>is an organic functional group) and hydrolyzed products of the silicon compounds and a water-soluble polymer having hydroxy groups and drying thermally. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a transparent laminate having retort suitability used in the packaging field that requires high gas barrier properties such as foods, non-foods, and pharmaceuticals and that requires retort processing.

  Packaging materials used for packaging foods, non-foods, pharmaceuticals, etc. are oxygen, water vapor, and other gases that alter the contents that permeate the packaging materials in order to suppress the alteration of the contents and maintain their functions and properties. It is necessary to prevent the influence of. And it is calculated | required to provide the gas barrier property which interrupts | blocks these gas (gas).

  Conventionally, in polymers, vinylidene chloride resin films having a relatively excellent gas barrier property or films coated with them have been used.

  However, they are greatly affected by gas barrier properties due to temperature and humidity. In addition, there are drawbacks such as inability to meet the demand for high gas barrier properties, which has been a problem. For this reason, a packaging material using a metal foil made of a metal such as aluminum as a gas barrier layer has been used for those requiring high gas barrier properties.

  However, packaging materials that use metal foils made of metal such as aluminum have high gas barrier properties without the influence of temperature and humidity, but there is a problem that the contents cannot be confirmed through the packaging material. there were.

  In addition, there is a problem that it must be treated as an incombustible material when discarded after use. Further, the metal detector cannot be used when inspecting whether foreign matter or the like is mixed in the packaged goods.

  Furthermore, since microwaves do not pass, there is a drawback that it cannot be used for foods such as microwave ovens.

  For this reason, as a packaging material that has overcome these drawbacks, for example, an inorganic oxide such as silicon oxide, aluminum oxide, and magnesium oxide described in Patent Document 1 and Patent Document 2 is formed on the polymer film. A film in which a deposited film is formed by a forming means such as a vacuum deposition method or a sputtering method is known.

  Also known is a heat-resistant transparent barrier film (see, for example, Patent Document 3) that enhances the adhesion between a plastic film and a deposited film and that does not deteriorate in performance even during sterilization treatment such as retort treatment.

  As shown in FIG. 2, the heat-resistant transparent barrier film 100 is subjected to pretreatment 102 using reactive ion etching (RIE) mode plasma on at least one surface of a base material 101 made of a plastic material, and further has a thickness of 5 A high aluminum oxide compound vapor deposition layer 103 made of AlOy (1.5 <(y / x) <= 3.0) of ˜100 nm is provided. A protective film layer 104 is formed on the upper surface of the high aluminum oxide compound vapor deposition layer 103.

These vapor-deposited films are known to have transparency, oxygen (RIE) mode, and gas barrier properties such as water vapor, and as a packaging material having both transparency and gas barrier properties that cannot be obtained with metal foil or the like. Is preferred.

Prior art documents are shown below.
U.S. Pat. No. 3,442,686 Japanese Patent Publication No.63-28017 JP 2005-335109 A

  However, even a film suitable for the packaging material described above is rarely used as a vapor deposition film alone as a packaging container or packaging material. And after vapor deposition, various processes such as printing on the surface of the vapor-deposited film as post-processing, or pasting together with other films, etc., and shape processing to packaging bodies such as containers After that, the package is completed.

  For this reason, gas barrier properties, such as oxygen permeability and water vapor permeability, were measured after carrying out a bag-making process by laminating a sealant film using the above-described deposited film or the like. As a result, it was not possible to obtain a film having a gas barrier property equivalent to that of a polymer gas barrier film or a gas barrier property equivalent to that of a metal foil.

  As a result, as a condition to be used as a packaging material that requires a high level of gas barrier properties, the metal that blocks transparency that can directly see through the contents, gas that affects the contents, etc. There is a new demand for gas barrier properties that are as high as foil.

  Furthermore, the versatility of packaging materials is required to be compatible with retort processing.

  The present invention has been made in view of the above-described conventional problems, and the problem is that it has a high level of gas barrier properties comparable to that of metal foil, and has high practical utility for retort with little barrier deterioration after retorting. It is providing the transparent laminated body which provided this.

In order to solve the above problems, the invention according to claim 1 of the present invention provides:
It is a transparent laminate that imparts retort suitability for a substrate made of a transparent plastic film,
One or both sides of the substrate made of the transparent plastic film is subjected to pretreatment by reactive ion etching (RIE) using plasma, and a vapor-deposited thin film layer made of an inorganic oxide, Si (OR ¹ ) ₄ and R ² Si (OR ³ ) ₃ (where R ¹ and R ³ are hydrolyzable groups such as C _n H _{2n + 1} , C _m H _2m , O · C _e H _{2l + 1} , and R ² is an organic functional group) Retort suitability characterized by comprising a laminate in which gas barrier coating layers are sequentially laminated by applying a solution in which a silicon compound represented by the formula or a hydrolyzate thereof and a water-soluble polymer having a hydroxyl group are mixed and dried by heating. It is the transparent laminated body which gave.

Next, the invention according to claim 2 of the present invention is as follows:
2. The transparent laminate having retort suitability according to claim 1, wherein the vapor deposition layer made of the inorganic compound is aluminum oxide and has a thickness of 5 to 300 nm.

Next, the invention according to claim 3 of the present invention is
The component ratio (Al / O) of aluminum oxide in the vapor deposition layer made of the inorganic compound is 30 to 50 as analyzed by EDX (energy dispersive X-ray fluorescence analyzer). 2. A transparent laminate having retort suitability described in 2.

Next, the invention according to claim 4 of the present invention is
The organic functional group (R ² ) of the R ² Si (OR ³ ) ₃ has a non-aqueous functional group such as vinyl, epoxy, methacryloxy, ureido, or isocyanate. It is the transparent laminated body which provided the retort aptitude as described in a term.

Next, the invention according to claim 5 of the present invention is
The retort suitability according to any one of claims 1 to 4, wherein the organic functional group (R ² ) of the R ² Si (OR ³ ) ₃ is an isocyanate in which an isocyanate group is polymerized. It is a transparent laminate.

Next, the invention according to claim 6 of the present invention is
6. The transparent laminate with retort suitability according to claim 1, wherein the gas barrier coating layer has a film hardness of 3.0 to 20.0 GPa.

Next, the invention according to claim 7 of the present invention is
The transparent laminate with retort suitability according to any one of claims 1 to 6, wherein the pretreatment by RIE according to claim 1 is a treatment using plasma.

Next, the invention according to claim 8 of the present invention is
The pretreatment by RIE according to claim 1 is carried out using one kind of gas of argon, nitrogen, oxygen, hydrogen, nitrous oxide, helium, or a mixed gas thereof, or subsequently these gases or mixed gases. The transparent laminated body imparted with retort suitability according to any one of claims 1 to 7, wherein the transparent laminated body is subjected to continuous treatment.

Next, the invention according to claim 9 of the present invention provides
The retort suitability according to any one of claims 1 to 8, wherein the pretreatment by the RIE and the deposition of the direction oxide are performed in the same film forming machine (in-line film forming machine). A transparent laminate.

  Since the transparent laminated body which provided the retort aptitude of this invention consists of the above structures, the contents can be visually observed easily from the outer surface of this transparent laminated body. In addition, a high level of gas barrier properties similar to general-purpose metal foils can be obtained. It can be used in a wide range of fields such as packaging and electronic device members. Furthermore, since there is little barrier deterioration by a retort process, the transparent laminated body which provided the retort aptitude with high practicality can be provided.

  The transparent laminated body which provided the retort suitability of this invention is demonstrated in detail, referring drawings below along embodiment.

  FIG. 1 is a schematic view showing an outline of an embodiment of a cross section of a transparent laminate to which retort suitability of the present invention is imparted.

As shown in FIG. 1, the transparent laminate to which the retort suitability of the present invention is imparted is subjected to a pretreatment (2) by RIE using plasma on at least one of a substrate (1) made of a transparent plastic. And the vapor deposition thin film layer (3) which consists of inorganic oxides, and the gas barrier film layer (4) are laminated | stacked in order on the upper surface.

  The base material (1) made of the transparent plastic described above is a transparent plastic material, and a transparent film is preferable in order to make use of the transparency of the deposited thin film layer. For example, polyester films such as polyethylene terephthalate (PET) and polyethylene naphthalate, polyolefin films such as polyethylene and polypropylene, polystyrene films, polyamide films, polyvinyl chloride films, polycarbonate films, polyacrylonitrile films, polyimide films, polylactic acid films, etc. Biodegradable plastic film or the like is used. And any of extending | stretching and unstretching may be sufficient, and what has mechanical strength and dimensional stability is good.

  Among the above films, polyethylene terephthalate arbitrarily stretched in a biaxial direction from the viewpoint of heat resistance and the like is particularly preferable.

  In addition, various known additives and stabilizers such as antistatic agents, ultraviolet inhibitors, plasticizers, lubricants, and the like can be used on the surface of the substrate (1) made of the transparent plastic.

  In order to improve the adhesion to the thin film, pretreatment may be performed by corona treatment, low-temperature plasma treatment, ion bombardment treatment, chemical treatment, solvent treatment, or the like.

  The thickness of the base material (1) made of the transparent plastic is 1 μm or more, suitability as a packaging material, and other layers may be laminated, a vapor-deposited thin film layer (3) made of an inorganic oxide, gas barrier properties Considering the workability in forming the coating layer (4), it is practically in the range of 3 to 200 μm and preferably 6 to 30 μm depending on the application.

  In consideration of mass productivity, it is desirable to use a long film so that each layer can be formed continuously.

  In general, as a packaging material, it is preferable that the base material (1) made of transparent plastic is a polyester film.

The polyester film usable in the present invention has a storage elastic modulus at a temperature of −20 ° C. to + 40 ° C. in the range of 9 × 10 ⁸ to 1 × 10 ¹⁰ Pa, and a β transition tan δ peak temperature of + 10 ° C. Any polyester film having dynamic viscoelasticity recognized below is not particularly limited.

Moreover, when the storage elastic modulus is less than 9 × 10 ⁸ Pa, the flexibility of the polyester film is insufficient, and impact resistance and pinhole resistance equivalent to those of the polyamide film cannot be obtained. On the other hand, when the storage elastic modulus exceeds 1 × 10 ¹⁰ , flexibility is sufficient, but handling properties as a stretched film are inferior.

  Furthermore, when the peak temperature due to the β transition of the polyester film 1 is not observed at + 10 ° C. or lower, the molecular chain cannot respond to an external load in the low temperature region, so that deformation in the low temperature region becomes difficult, and in the low temperature region, Insufficient bending pinhole resistance. Moreover, it is preferable that it is a transparent film base material if possible in order to make use of transparency of a vapor deposition thin film layer.

Examples of the polyester film having the above-described conditions include, for example, terephthalic acid, naphthalenecarboxylic acid, isophthalic acid, diphenyldicarboxylic acid, diphenylsulfone dicarboxylic acid, diphenoxyethanedicarboxylic acid, 5-sodium sulfone as dicarboxylic acid components constituting the polyester. Aromatic dicarboxylic acids such as isophthalic acid and phthalic acid, alicyclic dicarboxylic acids such as cyclohexyne dicarboxylic acid, and aliphatic dicarboxylic acids such as oxalic acid, succinic acid, adipic acid, sebacic acid, dimer acid, maleic acid, and fumaric acid And oxycarboxylic acids such as p-oxybenzoic acid.

  Examples of alcohol components include aliphatic glycols such as ethylene glycol, propanediol, 1,4 butanediol, 1,6 hexanediol, and neopentyl glycol, diethylene glycol, triethylene glycol, polyethylene glycol, polypropylene glycol, and 1,4 cyclohexane. Examples thereof include polyoxyalkylene glycols such as dimethanol, aromatic glycols such as bisphenol A and bisphenol S, and derivatives thereof.

  Among these polyesters, those mainly composed of polyethylene terephthalate are preferable from the viewpoints of film forming properties such as biaxial stretching properties, humidity properties, heat resistance, chemical resistance, and low cost. And within the range where the excellent physical properties of polyethylene terephthalate can be maintained, other alcohol components are controlled so as to be incorporated into the main chain in the polymerization stage and copolymerized, thereby causing a segment with little rotational hindrance in the molecular chain (soft segment) Is formed, and the force due to external impact or bending is absorbed by the soft segment in the molecular chain, resulting in excellent impact resistance and flexibility.

  For the transparent laminate to which retort suitability of the present invention is imparted, a copolyester in which 50 mol% or more of each of the carboxylic acid component and the alcohol component of the polyester is terephthalic acid, ethylene glycol, and derivatives thereof is preferably used.

  Regarding the stretching ratio of the polyester film, there are a sequential biaxial stretching process and a simultaneous biaxial stretching process, and the stretching ratio (vertical stretching ratio × horizontal stretching ratio) is preferably 5 to 20 times.

  Moreover, it is preferable that the hot-water heat shrinkage rate on 120 degreeC 30 minute conditions at the time of forming into a film on the said conditions shall be 4% or less in MD / TD direction. And if it exceeds 4%, since the shrinkage is large, the deterioration of the gas barrier property after post-processing becomes large.

  In order to improve the adhesion between the substrate (1) made of the transparent plastic film and the transparent vapor-deposited thin film layer (3) made of an inorganic oxide, the surface of the substrate (1) made of the transparent plastic film is made of plasma. Pretreatment (2) by active ion etching (RIE) is performed.

  By performing this RIE treatment, the generated radicals and ions are used to cause chemical effects such as imparting functional groups to the surface of the substrate (1) made of a transparent plastic film, and the surface is subjected to ion etching to produce impurities. It is possible to simultaneously obtain two physical effects such as scattering or smoothing.

  By performing such surface treatment, a dense thin film of inorganic oxide can be formed in the next vapor deposition step. As a result, the adhesion between the substrate (1) made of a transparent plastic film and the vapor-deposited thin film layer (3) made of an inorganic oxide can be strengthened, and the gas barrier property and moisture-proof property can be improved, and cracks in the vapor-deposited thin film layer can be generated. It also leads to prevention.

  The method of performing the processing by RIE with a roll-in type in-line apparatus is a method of generating plasma and reacting in several kinds of gases.

  Argon, oxygen, nitrogen, hydrogen, nitrous oxide, and helium can be used as gas species for performing the pretreatment by RIE. These gases may be used alone, or two or more kinds of gases may be mixed and used. Moreover, you may process continuously using several processor. At this time, it is not necessary to use the same plurality of processors.

  The type of gas to be used is determined by the energy given, effects, and ease of handling.

  The processing conditions for the pretreatment by RIE can be indicated by processing speed, energy level, and the like, and are set as appropriate according to the composition of the substrate (1), application, discharge device characteristics, and the like. However, it is preferable that the self-bias value of the plasma is 200 V or more and 2000 V or less, and even if the value is slightly lower than 200 V, it is possible to develop a certain degree of adhesion, but it has an advantage over the untreated one. Low.

  Moreover, when it is a high value exceeding 2000V, a strong process will be applied too much and the surface of the base material (1) which consists of a transparent plastic film will deteriorate, and it will become the cause for adhesiveness to fall. Furthermore, the gas used for plasma and the mixing ratio thereof may be appropriately set according to the film composition, application, and apparatus characteristics because the flow rate differs depending on the pump performance and the mounting position.

  Further, the vapor-deposited thin film layer (3) made of an inorganic oxide is made of a vapor-deposited film of an inorganic oxide such as aluminum oxide, silicon oxide, tin oxide, magnesium oxide, or a mixture thereof, and has transparency and oxygen, Any material having gas barrier properties such as water vapor may be used. Among these, aluminum oxide, silicon oxide, and magnesium oxide are particularly preferable because of their excellent oxygen transmission rate and water vapor transmission rate, and aluminum oxide is most preferable for bringing out the best effects of the present invention.

  When the component ratio of the aluminum oxide was analyzed by EDX (energy dispersive X-ray fluorescence spectrometer), Al / O = 34.8. In addition, the aluminum component ratio was compared, and (Al / O) of 30 to 50 is effective for gas barrier UP, particularly water vapor barrier property UP. If it is below 30, the transparency is high but it does not lead to the gas barrier UP, and if it is above 50, the barrier property is high but it becomes an aluminum film and the transparency is low.

  The EDX is a device that irradiates a sample with X-rays and takes reflected light (fluorescent X-rays) that varies depending on the element into a semiconductor detector to perform energy analysis. Since the energy differs between aluminum atoms and oxygen atoms, the ratio in the sample can be determined as qualitative analysis / quantitative analysis.

  The optimum thickness of the vapor-deposited thin film layer (3) made of an inorganic oxide varies depending on the type and configuration of the inorganic compound used, but is generally preferably in the range of 5 to 300 nm, and the value is appropriately selected. The However, if the film thickness is less than 5 nm, a uniform film may not be obtained or the film thickness may not be sufficient, and the function as a gas barrier material may not be sufficiently achieved.

  On the other hand, when the film thickness exceeds 300 nm, flexibility cannot be maintained in the thin film, and the thin film may be cracked due to external factors such as bending and pulling after the film formation. Preferably, it exists in the range of 5-100 nm.

There are various methods for forming the deposited thin film layer (3) made of an inorganic oxide on the pretreatment (2) layer by reactive ion etching (RIE) using plasma, and it is formed by a normal vacuum deposition method. However, other thin film forming methods such as sputtering, ion plating, and plasma vapor deposition (CVD) can also be used. However, considering productivity, the vacuum deposition method is the best at present.

  Further, as the heating means of the vacuum evaporation apparatus by the vacuum evaporation method, an electron beam heating method, a resistance heating method, an induction heating method, etc. are preferable. In order to improve the adhesion between the thin film and the substrate and the denseness of the thin film, plasma assist It is also possible to use an ion beam assist method. In addition, in order to increase the transparency of the deposited film, it is possible to carry out reactive deposition by blowing oxygen gas or the like during deposition.

The introduction of gas is related to the degree of vacuum (exhaust capacity of the apparatus). O ₂ / N ₂ is selected as the reaction gas for vapor deposition, and the amount of introduction is adjusted so as not to impair the degree of vacuum (exhaust capacity of the apparatus) in the apparatus that exhibits gas barrier properties.

  In addition, the gas barrier coating layer (4) is provided on the vapor deposition thin film layer (3) made of an inorganic oxide in order to impart a high level of gas barrier properties similar to a metal foil and to physically protect the vapor deposition thin film layer. Is provided.

In order to achieve this, the gas barrier coating layer (4) is made of Si (OR ¹ ) ₄ and R ² Si (OR ³ ) ₃ (where R ¹ and R ³ are C _n H _{2n + 1} , C _m H _2m , O · C _e H _{2l + 1 and} other hydrolyzable groups, R ² is an organic functional group) and a solution prepared by mixing a water-soluble polymer having a hydroxyl group and a hydrolyzate thereof is applied and heated. It is necessary to be a gas barrier coating layer formed by drying. Each component contained in the coating solution is described below.
R ² Si (OR ³ ) ₃ (where R ¹ and R ³ are hydrolyzable groups such as C _n H _{2n + 1} , C _m H _2m , O · C _e H _{2l + 1} , and R ² is an organic functional group) Generally, it is used as a silane coupling agent to improve the adhesion between the organic layer and the inorganic layer. The transparent laminate to which the retort suitability of the present invention is imparted is also necessary for improving the adhesion between the inorganic oxide film and the gas barrier coating layer.

Among them, the organic functional group (R ² ) having a non-aqueous functional group such as a vinyl group, an epoxy group, a ureido machine, or an isocyanate group is non-aqueous and has high resistance to hot water such as retort treatment. Isocyanurate polymerized with isocyanate groups is easy to handle in a gas barrier coating solution, slows the gelation of the coating solution, and improves adhesion without causing a barrier decrease due to the addition of a silane coupling agent. Is particularly preferable.

  The water-soluble polymer having a hydroxyl group used when producing a transparent laminate having the retort suitability of the present invention refers to polyvinyl alcohol, starch, and celluloses. In particular, when polyvinyl alcohol (hereinafter referred to as PVA) is used as a coating agent, gas barrier properties are most excellent. PVA as used herein is generally obtained by saponifying polyvinyl acetate, and saponification is complete saponification in which only several percent of acetic acid groups remain from so-called partially saponified PVA in which several tens of percent of acetic acid groups remain. It includes up to PVA and is not particularly limited.

The mixing method of the gas barrier coating layer solution used when producing the transparent laminate having the retort suitability of the present invention is a water-soluble polymer having hydrolyzed Si (OR ¹ ) ₄ and a hydroxyl group, R ² Si. (OR ³ ) The effect appears even if ₃ is mixed in any order. In particular, Si (OR ¹ ) ₄ and R ² Si (OR ³ ) ₃ are separately hydrolyzed and then added to the water-soluble polymer to improve the fine dispersion of SiO ₂ and the hydrolysis efficiency of Si (OR ¹ ) _4. This is desirable.

In consideration of adhesion to ink, adhesive, wettability, and prevention of cracking due to shrinkage to the coating solution of the gas barrier film, isocyanate compounds, clay minerals such as colloidal silica and smectite, stabilizers, colorants, Known additives such as viscosity modifiers can be added within a range that does not impair gas barrier properties and water resistance.

  Moreover, although the thickness after drying is not specifically limited, Since it will become easy to produce a crack when thickness exceeds 50 micrometers or more, it is desirable to set it as 0.01-50 micrometers.

  Further, the gas barrier coating layer (4) has a coating hardness after drying of the D layer measured by an ultra-fine indentation hardness tester (manufactured by NEC Corporation) in order to protect the deposited layer. It is preferable to be in the range of ˜20.0 GPa, more preferably in the range of 3.0 to 10.0 GPa. A film hardness of less than 3.0 GPa is not preferable because drying is insufficient and gas barrier properties are lowered.

  On the other hand, if the film hardness exceeds 20.0 GPa, the film becomes too hard, and it is not preferable because it cannot withstand external forces such as bending and expansion and contraction and is easily broken. And since the hardness of a film changes with the processing machines and processing conditions which apply, it is necessary to set the processing speed, air volume, and drying temperature matched to each.

  Moreover, as a gas barrier film layer (4) formation method, a normal coating method can be used. For example, dipping method, roll coating, gravure coating, reverse coating, air knife coating, comma coating, die coating, screen printing method, spray coating, gravure offset method and the like can be used. It apply | coats on a vapor deposition layer using these coating systems.

  Further, the drying method of the gas barrier coating layer (4) may be any of those methods that heat the gas barrier coating layer such as hot air drying, hot roll drying, high frequency irradiation, infrared irradiation, UV irradiation, etc. In any case, two or more of these may be combined.

  As a method for forming the gas barrier coating layer (4), a normal coating method can be used. For example, dipping method, roll coating, gravure coating, reverse coating, air knife coating, comma coating, die coating, screen printing method, spray coating, gravure offset method and the like can be used. It applies to the single side | surface or both surfaces of the base material 1 which consists of a transparent plastic film using these coating systems.

  As the drying method, any one of these may be used as long as it is a method of applying heat to the gas barrier coating layer such as hot air drying, hot roll drying, high frequency irradiation, infrared irradiation, UV irradiation, and the like, so as to eliminate water molecules. You may combine them.

  When the heat applied to the surface of the gas barrier coating layer (4) of the transparent laminate to which the retort suitability of the present invention is applied is a high temperature of 200 ° C. or higher, the barrier is further improved, and moisture resistance and water resistance are also improved. Further, by performing the heat treatment at 200 ° C. or higher, it is possible to maintain high barrier properties and adhesiveness without deterioration of the gas barrier coating layer even in the boil and retort treatment.

  This is because the hydrolysis of the hydrolyzed metal alkoxide contained in the gas barrier coating layer (4) proceeds, the water-soluble polymer is sufficiently dehydrated, and poly (meth) acrylic acid and water-soluble This is because chemical polymerization of the hydroxyl group of the polymer occurs.

Moreover, as a high-temperature heat treatment method at 200 ° C. or higher, a general hot air drying method or hot roll drying method can be used. Further, the same effect can be obtained by a flame treatment method in which the surface of the gas barrier coating layer (4) is heat-treated with a flame of several thousand degrees. And even if the stretch coating method which coats a liquid at the time of film stretching is effective if the heat setting temperature of a stretched film is 200 ° C or more.

  Moreover, it is also possible to laminate | stack a printing layer on a gas-barrier film layer (4) as needed. And it is also possible to laminate | stack several resin through an adhesive agent. A plurality of resins can be laminated on the opposite surface of the substrate 1 made of a transparent plastic film via a printing layer, a heat seal layer, and an adhesive layer.

  Hereinafter, the present invention will be described in more detail with reference to specific examples, but the present invention is not limited thereto.

<Example 1>
Storage modulus at −20 ° C. and + 40 ° C. when dynamic viscoelasticity measurement was performed under the measurement conditions of a frequency of 1 Hz, a heating rate of 2 ° C./min, and a measurement temperature range of −150 to + 150 ° C. Are 3.5 × 109 and 3.2 × 109 Pa, respectively, and the peak temperature of β transition tan δ is 0.6 ° C., the vertical stretching is 3.5 times, the horizontal stretching is 3.5 times, and the heat treatment temperature is 220 ° C. A biaxially stretched polyethylene terephthalate (PET) film having a thickness of 12 μm was used.

  The hot water shrinkage of the PET film at 120 ° C. for 30 minutes was MD 3.0% and TD 2.1%. One side of this PET film was pretreated by RIE using a plasma processor. At this time, a high frequency power source having a frequency of 13.56 MHz was used for the electrodes, and an argon / oxygen mixed gas was used for the processing gas.

  The plasma self-bias value at this time was 680V. Subsequently, a transparent vapor deposition thin film layer made of aluminum oxide having a thickness of 15 nm was laminated on the pretreatment layer by RIE on an in-line by a vacuum vapor deposition apparatus by an electron beam heating method. During vapor deposition, nitrogen gas was introduced simultaneously with oxygen gas. The introduction was performed as a mixed gas with oxygen gas. When the components of the transparent vapor-deposited thin film layer were analyzed by EDX (energy dispersive X-ray fluorescence spectrometer), Al / O = 34.8.

  Next, a coating agent having the following composition was applied by a gravure coating method, and then dried at 120 ° C. for 2 minutes to form a gas barrier coating layer (4) having a thickness of 0.5 μm and a film hardness of 8.0 GPa. The transparent laminated body a which gave was obtained. The film hardness was measured with an indentation depth of 0.1 μm using an ultra-fine indentation hardness tester (Nanoindenter) manufactured by NEC Corporation.

<Adjustment of gas barrier coating liquid>
(A) Tetraethoxysilane (Si (OC ₂ H ₅ ) ₄ ; hereinafter referred to as TEOS) 17.9 g and methanol 10 g were added 72.1 g of hydrochloric acid (0.1N) and stirred for 30 minutes to hydrolyze the solid content. 5% (weight ratio in terms of SiO ₂ ) hydrolysis solution.

  (B) 5% (weight ratio) of polyvinyl alcohol, water / methanol alcohol = 95/5 (weight ratio) aqueous solution.

(C) Hydrous acid prepared by adjusting 1,3,5-tris (3-trialkoxysilylalkyl) isocyanurate to a solid content of 5% (weight ratio R ² Si (OH) ₃ conversion) with water / IPA = 1/1 solution Decomposition solution.

(D): Hydrochloric acid (1N) was gradually added to β- (3,4 epoxy synchromexine) trimethoxine silane and isopropyl alcohol (IPA solution), stirred for 30 minutes, hydrolyzed, and then water / IPA = was hydrolyzed in 1/1 solution, hydrolyzed solution having a solid content of 5% (weight ratio R ² Si (OH) ₃ conversion).

(E) γ-glycidoxypropyltrimethoxysilane and IPA solution were gradually added with hydrochloric acid (1N), stirred for 30 minutes and hydrolyzed, then hydrolyzed with water / IPA = 1/1 solution, Hydrolysis solution adjusted to a solid content of 5% (weight ratio R ² Si (OH) ₃ conversion).

(F): Hydrochloric acid (1N) was gradually added to vinyltrimethoxysilane and IPA solution, stirred for 30 minutes, hydrolyzed, then hydrolyzed with water / IPA = 1/1 solution, solid content 5% Hydrolysis solution adjusted to (weight ratio R ² Si (OH) ₃ conversion).

<Composition of gas barrier coating agent>
Liquid A, liquid B and liquid C were mixed at a ratio of A / B / C = 70/20/10 (% by weight) to obtain a gas barrier coating liquid used for the transparent laminate having the retort suitability of the present invention. .

<Example 2>
The composition of the gas barrier coating agent of Example 1 is the same as that of Example 1 except that the D liquid is used instead of the C liquid.

<Example 3>
The composition of the gas barrier coating agent of Example 1 is the same as that of Example 1 except that E liquid is used instead of C liquid.

<Example 4>
The composition of the gas barrier coating agent of Example 1 is the same as that of Example 1 except that the liquid F is used instead of the liquid C.

<Comparative Example 1>
In the transparent laminate to which the retort suitability of Example 1 was imparted, a transparent laminate b was obtained in the same manner except that the pretreatment by RIE was not performed.

<Comparative example 2>
In the transparent laminate of Example 1, a transparent laminate c was obtained in the same manner except that no processing gas was used during the pretreatment by RIE.

<Comparative Example 3>
In the transparent laminated body of Example 1, the transparent laminated body d of this invention was obtained similarly except not having provided the gas barrier film layer.

<Comparative Example 4>
A transparent laminate e was obtained in the same manner as in the transparent laminate of Example 1, except that the composition ratio of the aluminum oxide deposited thin film layer (3) was Al / O = 25 by EDX.

<Comparative Example 5>
In the transparent laminated body of Example 1, the transparent laminated body f was obtained similarly except having set the composition ratio of the aluminum oxide vapor deposition thin film layer (3) to Al / O = 55 by EDX.

<Comparative Example 6>
In the transparent laminated body of Example 1, 7 micrometers instead of the aluminum oxide vapor deposition thin film layer (3)
A transparent laminate g was obtained in the same manner except that the aluminum foil was used.

<Comparative Example 7>
In Example 1, the transparent layered product h was obtained in the same manner as in Example 1 except that the gas barrier coating layer (4) 6 was dried at 70 ° C. for 1 minute to obtain a layer having a film hardness of 2.0 GPa.

<Comparative Example 8>
A transparent laminate i was obtained in the same manner as in Example 1, except that the gas barrier coating layer (4) 6 was dried at 130 ° C. for 5 minutes to obtain a layer having a film hardness of 22.0 GPa.

<Comparative Example 9>
A transparent laminate j was obtained in the same manner as Example 1 except that the pretreatment by RIE and the vapor deposition of the inorganic oxide were performed off-line in the transparent laminate to which retort suitability was imparted.

  Each of the obtained transparent laminates a to i was dry-laminated with a configuration of transparent laminate // ONy // CPP and subjected to a retort treatment at 121 ° C. for 30 minutes.

<Evaluation 1>
The oxygen permeability (cm ³ / m ² / day) and water vapor permeability (g / m ² · day) before and after the retort treatment of the laminates obtained in Examples 1 to 4 and Comparative Examples 1 to 9 were measured. did. The results are shown in Table 1.

<Evaluation 2>
The laminates obtained in Examples 1 to 4 and Comparative Examples 1 to 9 were measured for light transmittance at 350 nm using a light transmittance measuring device “UV-3100” (manufactured by Shimadzu Corporation). The results are shown in Table 1.

<Evaluation 3>
As the workability evaluation of the laminates obtained in Examples 1 to 4 and Comparative Examples 1 to 9, vapor deposition, coating, and post-processing (extrusion lamination) were targeted, and the quality was determined according to the situation. {(Good) ◎>○>Δ> × (defect)}. The results are shown in Table 1.

<Evaluation 4>
As a waste evaluation of the laminates obtained in Examples 1 to 4 and Comparative Examples 1 to 9, the quality was determined in the same manner as described above {(good) ◎>○>Δ> × (defect)}. The results are shown in Table 1.

<Evaluation 5>
As the cost evaluation of the laminates obtained in Examples 1 to 4 and Comparative Examples 1 to 9, the quality was determined in the same manner as described above from the viewpoint of material procurement, necessary equipment, possible loss, etc. {(Low) ◎> ○ >Δ> × (high)}. The results are shown in Table 1.

表１は酸素透過率、水蒸気透過率、光線透過率、加工性、廃棄性、コストの総合評価結果を記す。

Table 1 shows the comprehensive evaluation results of oxygen transmission rate, water vapor transmission rate, light transmission rate, processability, discardability, and cost.

<Evaluation results>
Examples 1-4 have a high gas barrier property, and there is also little barrier deterioration after a retort process. In addition, there are many benefits from industrial and commercial aspects.

  The transparent laminate to which the retort suitability of the present invention is imparted is an excellent invention that can be used not only for packaging materials that can be used for packaging in the packaging field and precision machinery field, but also for members in the building field.

It is the schematic which shows the outline of one Example of the transparent laminated body cross section which provided the retort aptitude of this invention. It is the schematic which shows the outline of the cross section of the conventional laminated material.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Base material which consists of transparent plastic films 2 ... Pre-processing surface which consists of RIE 3 ... Vapor deposition thin film layer which consists of inorganic oxides 4 ... Gas barrier coating layer 5 ... Intermediate layer (ONy)
6 ... Heat seal layer (CPP)
7 ... Transparent laminate

Claims (9)

It is a transparent laminate that imparts retort suitability for a substrate made of a transparent plastic film,
One or both sides of the substrate made of the transparent plastic film is subjected to pretreatment by reactive ion etching (RIE) using plasma, and a vapor-deposited thin film layer made of an inorganic oxide, Si (OR ¹ ) ₄ and R ² Si (OR ³ ) ₃ (where R ¹ and R ³ are hydrolyzable groups such as C _n H _{2n + 1} , C _m H _2m , O · C _e H _{2l + 1} , and R ² is an organic functional group) Retort suitability characterized by comprising a laminate in which gas barrier coating layers are sequentially laminated by applying a solution in which a silicon compound represented by the formula or a hydrolyzate thereof and a water-soluble polymer having a hydroxyl group are mixed and dried by heating. The transparent laminated body which gave.   2. The transparent laminate having retort suitability according to claim 1, wherein the vapor deposition layer made of the inorganic compound is aluminum oxide and has a thickness of 5 to 300 nm.   The component ratio (Al / O) of aluminum oxide in the vapor deposition layer made of the inorganic compound is 30 to 50 as analyzed by EDX (energy dispersive X-ray fluorescence analyzer). The transparent laminated body which provided the retort aptitude of 2. The organic functional group (R ² ) of the R ² Si (OR ³ ) ₃ has a non-aqueous functional group such as vinyl, epoxy, methacryloxy, ureido, or isocyanate. The transparent laminated body which provided the retort aptitude as described in a term. The retort suitability according to any one of claims 1 to 4, wherein the organic functional group (R ² ) of the R ² Si (OR ³ ) ₃ is an isocyanate in which an isocyanate group is polymerized. Transparent laminate.   The transparent laminate with retort suitability according to any one of claims 1 to 5, wherein the gas barrier film layer has a film hardness of 3.0 to 20.0 GPa.   The transparent laminate with retort suitability according to any one of claims 1 to 6, wherein the pretreatment by RIE according to claim 1 is a treatment using plasma.   The pretreatment by RIE according to claim 1 is carried out using one kind of gas of argon, nitrogen, oxygen, hydrogen, nitrous oxide, helium, or a mixed gas thereof, or subsequently these gases or mixed gases. The transparent laminated body which provided the retort aptitude of any one of Claims 1 thru | or 7 characterized by being the process performed using continuously.   The retort suitability according to any one of claims 1 to 8, wherein the pretreatment by the RIE and the deposition of the direction oxide are performed in the same film forming machine (in-line film forming machine). Transparent laminate.

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