JP4334609B2 - Production method of deoxidizing resin film - Google Patents

Description

  The present invention relates to a deoxygenating resin composition for absorbing and removing oxygen in an atmosphere and a deoxygenating resin composition manufacturing apparatus and method for manufacturing a film, and a deoxygenating resin film manufacturing apparatus and method.

In recent years, in response to strong demands for food safety and quality maintenance, it has been carried out to suppress oxidative degradation of food by making the inside of a food packaging body for packaging food anaerobic.
Specifically, an oxygen scavenger that absorbs and removes oxygen in the atmosphere is placed inside the food packaging body together with the food, and residual oxygen inside the food packaging body is removed to eliminate the inside of the food packaging body. An oxygen state is performed. In addition, in an inert gas not containing oxygen, the food is packaged together with the oxygen scavenger in a food packaging body so as not to allow oxygen to enter the food packaging body, and the food packaging body includes A slight amount of oxygen that permeates and penetrates into the inside is also removed by an enclosed oxygen scavenger.

  As described above, oxygen scavengers that remove oxygen in the atmosphere include organic materials and inorganic materials. From the viewpoint of cost, iron-based oxygen scavengers are inorganic materials. Agents are mainly used. As shown in the following chemical formula (1), this iron-based oxygen scavenger removes oxygen from the atmosphere by reacting iron with oxygen in the atmosphere together with slight moisture in the atmosphere. Yes.

Fe + 1 / 2H ₂ O + 3 / 4O ₂ → FeOOH (1)

  In particular, in recent years, a deoxidation film utilizing the oxidation reaction of iron represented by the above chemical formula (1) has been developed. By using this film as a packaging material (so-called “packaging material”), an oxygen scavenger is separately added. An oxygen scavenging package that is not necessary has been developed (Patent Document 1).

However, when the conventional iron-based deoxygenated film as described above is used, there are the following problems.
(1) The performance of conventional deoxygenated films is necessary when storing foods that dislike moisture, such as dried foods, electronic parts, and solder powder, because they require a small amount of moisture when reacting with oxygen. There is a problem that cannot be fully demonstrated.
(2) When examining whether or not foreign substances such as metals are mixed in foods packaged with conventional deoxygenated films, a metal detector reacts with iron-based deoxygenated films, and a simple examination is performed. There is a problem that it cannot be done.
(3) There is a problem that it is rapidly heated by a microwave such as a microwave oven and ignites.
(4) Further, there is a problem that when iron is oxidized, it turns brown and looks bad.
(5) Further, the iron rust smell when iron is oxidized affects the flavor and the like of the contents, which becomes a problem particularly when maintaining high quality in medicines and foods.

  For this reason, oxygen-absorbing resin compositions or films using inorganic oxides such as titanium oxide instead of iron-based oxygen absorbers or films have been proposed (Patent Documents 2 to 6).

  However, there is a problem that the oxygen absorbing ability using only an inorganic oxide such as titanium oxide is not sufficient for oxygen absorption.

  Then, in the said inorganic oxide, it discovered previously that cerium oxide was suitable as a deoxidizer instead of the said titanium oxide, and proposed previously (patent documents 7 and 8).

  By the way, since the cerium oxide-based oxygen absorber absorbs oxygen relatively quickly, it is dispersed in, for example, a polyolefin resin without deteriorating the oxygen absorption capacity of the cerium oxide-based oxygen absorber, and the oxygen-absorbing resin composition and the oxygen-removing resin composition are removed. There is a problem that it is difficult to manufacture an oxygen film.

  Therefore, the advent of a deoxygenating resin composition and a deoxygenating film manufacturing apparatus that have industrially established handling operations when kneading a cerium oxide-based oxygen scavenger into a resin and forming a film has been eagerly desired.

JP 2003-37823 A JP 2005-104064 A JP 2005-105194 A JP 2005-105195 A JP 2005-105199 A JP 2005-105200 A JP 2007-185653 A JP 2007-222868 A

  In view of the above problems, the present invention provides an apparatus for producing a deoxygenating resin composition and a deoxygenating resin industrially established handling operation when a cerium oxide-based oxygen scavenger having oxygen defects is kneaded into a resin and formed into a film. It is an object of the present invention to provide an apparatus and method for producing an oxygen film and an apparatus and method for producing a deoxygenating resin film.

The first invention of the present invention for solving the above-mentioned problem is that a cerium oxide-based oxygen scavenger having a reversible oxygen defect generated by forced extraction of oxygen and an oxygen-permeable resin are kneaded and A kneading extruder for extruding;
A cooling bath that cools the extrudate without reducing the oxygen absorption capacity of the extruded extrudate;
A cutting machine for cutting the extrudate after cooling into chips,
An apparatus for producing a deoxidizing resin composition, wherein the cerium oxide-based deoxidizing agent having oxygen defects is kneaded while being supplied in a non-oxygen atmosphere.

  According to a second aspect of the present invention, there is provided the deoxygenating resin composition according to the first aspect, wherein the cooling medium of the cooling tank that cools without reducing the oxygen absorption capacity is oxygen-free water or alcohol. In the device.

  According to a third aspect of the present invention, there is provided the deoxygenating resin composition according to the first aspect, wherein the cooling medium of the cooling tank that cools without reducing the oxygen absorption capacity is nitrogen or nitrogen-enriched air. In production equipment.

  A fourth invention is characterized in that, in the second invention, a dryer is interposed between the cooling tank and the cutting machine, and a vacuum dryer is provided on a subsequent process side of the cutting machine. It exists in the manufacturing apparatus of the deoxygenating resin composition to do.

  According to a fifth invention, in any one of the first to fourth inventions, the cerium oxide-based oxygen scavenger has an oxygen absorption site due to reversible oxygen deficiency caused by forced extraction of oxygen, and In the apparatus for producing a deoxygenating resin composition, at least a part of an oxygen absorption site is removably blocked by a site blocking factor body.

According to a sixth aspect of the present invention, there is provided the apparatus for producing a deoxygenating resin composition according to the fifth aspect, wherein the site blocking factor body is carbon dioxide (CO ₂ ).

  According to a seventh invention, in any one of the first to sixth inventions, magnesium (Mg), calcium (Ca), strontium (Sr), lanthanum (La), niobium (Nb), praseodymium (Pr) or yttrium ( Y) A deoxygenating resin composition manufacturing apparatus, wherein any one of these or a mixture thereof is dissolved in the cerium oxide-based oxygen scavenger.

The eighth invention is an extrusion molding machine for extruding a cerium oxide-based deoxygenating resin composition into a sheet,
A winding device having a take-up roller for taking up the sheet-like material and a take-up roller for taking up the taken-up sheet-like material;
A temperature controller for adjusting the temperature of the take-up roller,
An apparatus for producing a deoxygenating resin film, wherein the winding device is configured to have a non-oxygen atmosphere.

  According to a ninth invention, in the eighth invention, the cerium oxide-based oxygen scavenger resin composition is obtained by the apparatus for producing an oxygen scavenging resin composition according to any one of claims 1 to 7. In an apparatus for producing a deoxygenating resin film.

  In a tenth aspect of the invention, a cerium oxide-based oxygen scavenger having reversible oxygen defects generated by forced extraction of oxygen is supplied in a non-oxygen atmosphere, kneaded and extruded with an oxygen-permeable resin, and then extrudate. Is cooled without decreasing the oxygen absorption capacity, and the extrudate after cooling is cut into chips to produce a deoxygenating resin composition.

  An eleventh invention is characterized in that, in the tenth invention, the cooling medium of the cooling tank that cools without reducing the oxygen absorption capacity is oxygen-free water, alcohol, nitrogen, or nitrogen-enriched air. It exists in the manufacturing method of an oxygen-based resin composition.

  In a twelfth aspect of the invention according to the tenth or eleventh aspect of the invention, the cerium oxide-based oxygen scavenger has an oxygen absorption site due to reversible oxygen deficiency caused by forced extraction of oxygen. In the method for producing a deoxygenating resin composition, at least a part thereof is removably blocked with a site blocking factor body.

A thirteenth invention is the method for producing a deoxygenating resin composition according to the twelfth invention, wherein the site blocking factor body is carbon dioxide (CO ₂ ).

  In a fourteenth aspect based on any one of the tenth to thirteenth aspects, magnesium (Mg), calcium (Ca), strontium (Sr), lanthanum (La), niobium (Nb), praseodymium (Pr) or yttrium ( Y) A method for producing a deoxidizing resin composition, wherein any one of these or a mixture thereof is dissolved in the cerium oxide-based deoxidizing agent.

  According to a fifteenth aspect of the present invention, when a cerium oxide-based deoxygenating resin composition is extruded into a sheet-like material, the cerium oxide-based deoxygenating resin composition is drawn while adjusting the temperature of a take-up roller for taking up the sheet-like material, It exists in the manufacturing method of the deoxidation resin film characterized by setting it as atmosphere.

It is the schematic of the manufacturing apparatus of the deoxidizing resin composition concerning this Embodiment. It is the schematic of the manufacturing apparatus of the other deoxidizing resin composition concerning this Embodiment. After reduction treatment the cerium oxide powder is a schematic view of a manufacturing process for obtaining a carbon dioxide (CO ₂₎ treatment to package filled with an oxygen scavenger. It is the schematic of a deoxidation film laminated body. It is the schematic of another deoxygenation film laminated body. It is the schematic of another deoxygenation film laminated body. It is the schematic of the manufacturing apparatus of a deoxidation resin film. FIG. 5 is a relationship diagram between a cerium oxide filling amount and a take-up roller temperature. It is the schematic of the laminated body of the deoxidation film which concerns on a present Example. It is the schematic of the package body of the deoxidation film which concerns on a present Example. It is a figure which shows the result (the relationship between elapsed time and oxygen concentration) of the deoxygenation test which concerns on a present Example.

  Hereinafter, the present invention will be described in detail with reference to the drawings. The present invention is not limited to the embodiments and examples. In addition, constituent elements in the following embodiments and examples include those that can be easily assumed by those skilled in the art or those that are substantially the same.

[First Embodiment]
FIG. 1 is a schematic view of an apparatus for producing a deoxidizing resin composition according to the present embodiment.
As shown in FIG. 1, a deoxygenating resin composition manufacturing apparatus 10 </ b> A has a biaxial shaft having a first feeder 12-1 for introducing a resin 11 and a second feeder 12-2 for introducing an oxygen scavenger 13. The kneading extruder 14, the liquid cooling tank 16A for cooling the rod-like strand 15 extruded from the die 14a of the extruder 14, the dryer 17 for drying the strand 15 after cooling, and the strand after drying are cut. Thus, the cutting machine 19 is made into a chip-shaped resin composition 18 and a receiving container 20 for receiving the chip-shaped resin composition 18.

  Here, the biaxial kneader-extruder 14 puts the resin 11 into the first feeder 12-1 and feeds the cerium oxide-based oxygen scavenger 13 into the second feeder 12-2. When the cerium-based oxygen scavenger 13 is charged, it is supplied in a non-oxygen atmosphere (for example, nitrogen purge) to prevent the oxygen scavenging performance of the oxygen scavenger 13 from deteriorating. In this specification, the non-oxygen atmosphere refers to an atmosphere that substantially does not contain oxygen. The term “substantially free” means that oxygen is contained to the extent that the oxygen scavenging ability of the oxygen scavenger is not impaired.

  The biaxial kneading extruder 14 has a screw and a paddle (not shown) rotating, and is kneaded while being pushed forward while maintaining a predetermined temperature. In addition, by providing a vacuum line, it is possible to prevent the resin from containing bubbles.

  In the present embodiment, the die 14a of the twin-screw kneading extruder 14 has five holes, from which the strand 15 that is an extrudate made of resin and cerium oxide is extruded in a rod shape.

  In the liquid cooling tank 16A, the strand 15 is immediately passed through the water cooling tank to cool it, and it is desirable that the refrigerant be oxygen-free water or alcohol. The amount of oxygen in the oxygen-free water is preferably 2.5 ppm or less, particularly 1 ppm or less. As the alcohol, it is desirable to use methanol, ethanol, propanol, or ethylene glycol.

  The dryer 17 dries the water-cooled strand 15, and the drying medium is preferably nitrogen-enriched air and an inert gas, and particularly preferably an inert gas. As the inert gas, nitrogen, carbon dioxide, rare gas (He, Ne, Ar) or the like can be used.

  The cutting machine 19 cuts the strands 15 that have passed through the dryer 17 into chips (or pellets) to form chip-shaped resin compositions 18, and the collection part of the receiving container 20 is also inert. It is preferable to perform a gas purge.

  Although not shown in FIG. 1, a vacuum dryer that vacuum-drys the chip-shaped resin composition 18 is provided on the downstream side of the cutting machine 19 to further remove moisture, thereby reducing the deoxygenation ability. You may make it prevent.

As shown in the deoxygenating resin composition manufacturing apparatus 10 </ b> B of FIG. 2, a gas cooling tank 16 </ b> B may be used as a cooling tank for cooling the strand 15.
Here, an inert gas is preferably used for the gas cooling tank 16B, but nitrogen or nitrogen-enriched air having an oxygen concentration of 5% or less may be used.
Thereby, the fall of the deoxidation capability at the time of cooling the strand 15 can be suppressed.

  As shown in FIG. 2, when the strand 15 is cooled using the gas cooling tank 16B, the dryer 17 and the vacuum dryer as shown in FIG. 1 are not necessary, and the apparatus configuration can be simplified.

  The cerium oxide-based oxygen scavenger having oxygen defects has oxygen defects formed by reducing cerium oxide and forcibly extracting oxygen from the crystal lattice. This oxygen defect is capable of absorbing oxygen. This oxygen absorption occurs in a living environment atmosphere. In the present specification, a high-temperature and / or high-pressure harsh atmosphere such as exhaust gas discharged from a power engine operating with fossil fuel is not included in this living environment atmosphere. The living environment atmosphere refers to a general atmosphere when storing products such as food, electronic parts, and pharmaceuticals. The atmospheric pressure includes, for example, a reduced pressure state (vacuum packaging or the like) in a product packaging, and a pressurized state (pressurization / heat sterilization in retort processing, packaging shape maintenance use, or the like). About temperature, about -50 degreeC (at the time of frozen storage) to 180 degreeC (retort processing of a foodstuff) is included. The atmosphere is not necessarily air, but may be purged with an inert gas such as nitrogen gas to reduce the oxygen concentration. The reduction treatment is performed in a strong reducing atmosphere in which a reducing gas such as hydrogen gas, acetylene gas, or carbon monoxide gas has a high concentration and is a high-temperature heat treatment.

  It is known that there are two types of oxygen deficiency possessed by cerium oxide: reversible deficiency and irreversible deficiency. The reversible defect is an oxygen defect of the cerium oxide constituting the oxygen scavenger of the present invention, and is generated when oxygen is forcibly extracted by treatment under strong reducing conditions. A reversible defect is a defect in which oxygen can be taken into a deficient site. In cerium oxide having a reversible defect, an unbalanced state of electric charge caused by oxygen deficiency is compensated by reducing a part of tetravalent cerium to trivalent. Trivalent cerium is unstable and easily returns to tetravalent. Therefore, by incorporating oxygen into the deficient site, trivalent cerium returns to tetravalent, and the charge balance is always kept at zero.

On the other hand, an irreversible defect is formed by doping cerium oxide with an element having a valence lower than that of cerium. An irreversible defect, unlike a reversible defect, is not a defect caused by treatment under strong reducing conditions. The irreversible deficiency is obtained, for example, by mixing an oxide of an element having a valence lower than that of cerium oxide with cerium oxide having no oxygen deficiency and firing in the atmosphere. All valences of cerium in cerium oxide with irreversible defects are tetravalent. Therefore, oxygen is not taken into the deficient site. For example, when 20 mol% of Ca is dissolved in CeO ₂ (Ce _0.8 Ca _0.2 O ₂ ), the average cation valence is 4 × 0.8 + 2 × 0.2 = 3.6. The number of oxygen atoms for balancing this valence is 3.6 ÷ 2 = 1.8, and the number of necessary oxygen atoms is less than two. Oxygen deficiency occurs accordingly. However, this oxygen deficiency is not capable of absorbing oxygen. Thus, the irreversible defect is not caused by forced extraction of oxygen but is caused by charge compensation in cerium oxide.

  By the way, in addition to cerium oxide having reversible oxygen vacancies used in the present invention, OSC (oxygen storage and release ability) materials are known as inorganic oxides capable of absorbing oxygen. OSC materials are often used as promoters for automotive catalysts. The OSC material is a material that uses oxygen ion conductivity and valence change of cerium oxide to take in oxygen from the atmosphere and simultaneously release oxygen to keep the amount of oxygen in the atmosphere constant. However, the uptake and release of oxygen by the OSC material occurs for the first time at a high temperature of several hundred degrees Celsius. Therefore, oxygen uptake and release by the OSC material does not occur in the living environment atmosphere in the atmosphere. This is because the OSC material does not have reversible oxygen deficiency in the living environment atmosphere.

  The oxygen absorption amount of cerium oxide having reversible oxygen deficiency used in the present invention is extremely high, close to the theoretical limit of 5 to 37 mL / g, particularly 15 to 34 mL / g, at 25 ° C. and 1 atmosphere. is there. The theoretical limit of oxygen absorption of cerium oxide having reversible oxygen deficiency is 37.2 mL / g.

The oxygen absorption is measured by the following method. 2 g of cerium oxide having reversible oxygen vacancies is collected and encapsulated in a package having air resistance (air resistance of 10 to 1000000 seconds). The size of the package having air permeability resistance is not particularly limited as long as it can contain 2 g of cerium oxide. Separately from this, a package having the same material and the same size and the same air permeability resistance that does not contain cerium oxide having reversible oxygen deficiency is prepared. Note that this operation is desirably performed under an inert atmosphere such as nitrogen or argon. Next, the produced package containing cerium oxide is exposed to the atmosphere (25 ° C., 1 atm), and the weight is measured with a precision electronic balance (4 digits or more after the decimal point) at regular intervals. Since the increase in weight is due to the absorption of oxygen, the amount of absorbed oxygen can be determined using the gas equation of state. In addition, in order to correct the weight increase due to moisture adsorbed on the package itself, the weight of the package that does not contain cerium oxide is also measured, and the weight is calculated from the weight of the package that contains cerium oxide. Decrease. Here, the air resistance is measured in accordance with JIS P8117, which means the time until the air 100mL finishes transmission at pressure difference 1.23kPa an area of 0.000642m ^2.

An element that increases the amount of oxygen absorbed by cerium oxide can be added to cerium oxide having reversible oxygen vacancies. The element to be added is preferably an element having an ionic radius in the vicinity of the ionic radius of cerium oxide, but is not limited to this as long as the oxygen absorption amount is increased by the addition.
Here, as the added metal, for example, magnesium (Mg), calcium (Ca), strontium (Sr), lanthanum (La), niobium (Nb), praseodymium (Pr), or yttrium (Y) or Mention may be made of these mixtures.
As addition amount, it is preferable to set it as 1-20 mol%. This is because if the amount is less than 1 mol%, the amount of the effect of addition is small.

  The cerium oxide-based oxygen scavenger has an oxygen absorbing ability and a dehumidifying function, and thus can be a deoxygenating composition and film having a dehumidifying function.

In cerium oxide, oxygen is forcibly extracted from the crystal lattice by a high-temperature reduction treatment to be in an oxygen deficient state (CeO _2-x ) as shown in the following formula (2), and has oxygen absorption sites. This oxygen deficient state is the above-described reversible deficiency. And since this oxygen absorption site reacts with oxygen in the atmosphere as shown in the following formula (3), the effect as an oxygen scavenger is exhibited. Since cerium oxide has a fluorite structure (Fluorite-Type), it is structurally stable and can stably hold an oxygen absorption site due to oxygen deficiency. Further, since the oxygen ion conductivity is high, oxygen can enter and exit to the inside, and the oxygen absorption ability is good.
CeO ₂ + xH ₂ → CeO _2−x + xH ₂ O (2)
CeO _2-x + (X / 2) O ₂ → CeO ₂ (3)

  The reduction treatment is performed in a strong reducing atmosphere in which the concentration of a reducing gas such as hydrogen gas, acetylene gas, or carbon monoxide gas is high and heat treatment is performed at a high temperature. The reducing gas concentration is preferably not less than the lower limit of explosion to 100% by volume, more preferably 20% to 100% by volume. The treatment temperature is preferably 500 ° C or higher, more preferably 700 ° C to 1200 ° C, and still more preferably 1000 ° C to 1050 ° C. The strongly reducing atmosphere is generally atmospheric pressure, but pressure conditions may be used instead.

In the present invention, the activity may be controlled by detachably blocking the oxygen absorption site with a site blocking factor body.
That is, it is preferable that the cerium oxide-based oxygen scavenger according to the present invention is such that at least a part of the oxygen absorption site is removably blocked by the site blocking factor body.
Specifically, as the site blocking factor body, one having a carbonyl group such as carbon dioxide (CO ₂ ) can be used.

Using this carbon dioxide, at least a part of the oxygen absorption site is removably blocked by a site blocking factor body, so that reduced cerium oxide (CeO _2-x ) having a reversible oxygen deficiency by reduction. By covering the surface with carbon dioxide (CO ₂ ), attack of oxygen (O ₂ ) can be inhibited, activity can be reduced, and ignition can be suppressed.

Here, a method of coating the surface of reduced cerium oxide (CeO _2-x ) with carbon dioxide (CO ₂ ) will be described with reference to FIG.
As shown in FIG. 3, cerium oxide powder (or a composite oxide in which a metal is dissolved) 200 is fired in a firing furnace 201 (300 to 1100 ° C .: 1 hour), and then in a reduction firing furnace 202 in a hydrogen atmosphere. Reduce with Thereafter, CO ₂ coating treatment was performed by a carbon dioxide (CO ₂ ) treatment apparatus 203. Thereafter, the film pack is applied by the film pack processing apparatus 204 to obtain a package 205 filled with the oxygen scavenger containing the powder oxygen scavenger.
Using the package 205 filled with the oxygen scavenger, the oxygen scavenger is supplied to the second feeder 12-2 of the twin-screw kneading extruder 14 shown in FIG. Kneading is done.

  As resin which mix | blends the cerium oxide type | system | group oxygen scavenger of this invention, a thing with an oxygen permeable property can be used, for example. For example, polyethylene (ultra low density polyethylene, low density polyethylene, low density linear polyethylene, medium density polyethylene), polypropylene, polystyrene, ethylene-propylene copolymer, ethylene-propylene random polymer, ethylene-α olefin copolymer, ethylene -Vinyl acetate copolymer, ethylene propylene rubber, ethylene-ethyl acrylate copolymer. As the resin, a resin having an oxygen gas barrier property can also be used. Examples of such resins include polyethylene terephthalate, polyvinyl alcohol, polyvinyl chloride, polyvinylidene chloride, terephthalic acid-trimethylhexamethylenediamine polycondensate, 2,2-bis (p-aminocyclohexyl) propane-adipic acid copolymer Examples of the polymer include ethylene vinyl alcohol copolymer, nylon MXD (trade name), nylon 6 (trade name), nylon 6,6 (trade name), and acrylic resin. Whether to use an oxygen-permeable resin or a resin having an oxygen gas barrier property as the resin is appropriately selected depending on the specific use of the deoxidizing resin composition according to the present invention. Good.

  As a method of blending the cerium oxide-based oxygen scavenger 13 into the resin 11, as shown in FIG. 1, the oxygen absorber is kneaded and dispersed in the heat-melted resin using a twin-screw kneading extruder 14 or the like. -The method of extruding is preferable, and it is preferable to make the obtained strand 15 into a chip shape (pellet shape) for the packaging material of the next process.

  At this time, in the supply of the oxygen scavenger 13, the cooling tank 16 </ b> A, the dryer 17, and the receiving container 20, a decrease in the oxygen scavenging ability of the oxygen scavenger can be significantly suppressed by setting each in a non-oxygen atmosphere.

  Therefore, according to the present invention, a deoxygenating resin composition can be produced by dispersing in a resin without reducing the oxygen absorption capacity of a cerium oxide-based oxygen absorber having a relatively high oxygen absorption rate. .

As a packaging material using the chip-shaped resin composition 18 of the present invention, various forms such as a film, a sheet, a cup, a tray, a cap, and an emboss can be used.
Here, since the purpose of use of the packaging material is to absorb oxygen inside the sealed packaging when the contents (preserved material) are sealed and packaged, the configuration in the case of the packaging material is deoxygenating An oxygen barrier layer needs to be disposed on the entire surface of the packaging material outside the resin layer.

Thus, according to the present embodiment, a deoxygenation film and a resin composition that exhibit a deoxygenation function using cerium oxide, which is an inorganic oxide, and a deoxygenation method in a sealed atmosphere using these are provided. be able to.
Therefore, for example, pharmaceuticals, supplements, chemicals (for example, dyes, fragrances, lipids, enzymes, vitamins, fatty acids) or food materials that are easily oxidized, foods, precision machinery and parts thereof, semiconductor substrates, and the like can be stably stored. It becomes possible.

[Second Embodiment]
In the present embodiment, film formation using a cerium oxide-based deoxygenating resin composition will be described.
The chip-shaped resin composition 18 may be used as a deoxygenated film laminate 50A as shown in FIG. As shown in FIG. 4, this deoxygenated film laminate 50A is provided with a deoxygenated layer 51 in which the chip-like resin composition 18 is formed into a film and on one surface side of the deoxygenated layer 51, and has an oxygen gas barrier property. And a gas barrier layer 53 provided on the other surface side of the deoxidation layer 51 and having oxygen gas permeability. This deoxygenated film laminate 50A is used so that the gas easily permeable layer 53 side faces an atmosphere where deoxidation is desired. In FIG. 4, a protective layer 54 is provided outside the gas barrier layer 52 to protect the gas barrier layer 52. Here, in FIG. 4, the code | symbol 55 illustrates oxygen.

  Here, as the gas barrier layer 52, metal foil such as aluminum foil, various resins such as polyethylene terephthalate, polyvinyl alcohol, polyvinyl chloride, polyvinylidene chloride, terephthalic acid-trimethylhexamethylenediamine condensation polymer, 2, 2 -Bis (p-aminocyclohexyl) propane-adipic acid copolymer, ethylene vinyl alcohol copolymer, nylon MXD (trade name), nylon 6 (trade name), nylon 6, 6 (trade name), acrylic resin, etc. Although what consists of a single layer or a multilayer can be illustrated, this invention is not limited to these.

Examples of the gas easily permeable layer 53 include polyethylene (ultra-low density polyethylene, low density polyethylene, low density linear polyethylene, medium density polyethylene), polypropylene, polystyrene, ethylene-propylene copolymer, ethylene-propylene random weight. Examples of the polymer, ethylene-α olefin copolymer, ethylene-vinyl acetate copolymer, ethylene propylene rubber, ethylene-ethyl acrylate copolymer, and the like can be exemplified by the present invention. It is not limited to these, For example, the layer which consists of fibers, such as paper and a nonwoven fabric, can also be used.
Further, the gas permeable layer 53 may be used in combination with the function of a sealant layer (for example, a polyolefin such as PP or PE).

  Examples of the protective layer 54 include polyethylene, polypropylene, polyethylene terephthalate (PET), and polyamide, but the present invention is not limited to these.

Moreover, as shown in the deoxidized film laminate 50B of FIG. 5 which is a modified example of FIG. 4, a buffer layer 57 is provided between the deoxygenated layer 51 and the gas barrier layer 52, and the adhesion and buffer properties are improved. You may make it give to.
Further, an advanced gas barrier layer 58 may be provided between the gas barrier layer 52 and the protective layer 54 to improve the certainty of preventing the invasion of gas from the outside.

  Here, as the buffer layer 57, for example, a resin having a buffering action and an adhesive action such as polyethylene and polypropylene can be exemplified, but the present invention is not limited thereto.

  Examples of the advanced gas barrier layer 58 include various metal foils including aluminum foil, aluminum vapor deposition films, various oxide (silica, titania, zirconia, alumina) vapor deposition films and the like. It is not limited to these.

  By using the deoxygenated film 50B having a six-layer structure as shown in FIG. 5, the buffering action is improved and the intrusion of gas from the outside becomes difficult, so that a film with higher added value can be provided.

  In addition to the oxygen absorption function, the cerium oxide-based deoxygenating resin composition having oxygen defects according to the present invention also exhibits a water absorption function because cerium oxide and water react to form a hydrate. Thus, as shown in the deoxygenated film laminate 50C having the dehumidifying function in FIG. 6, moisture 59 can be absorbed in addition to the oxygen 55 existing inside.

Next, a manufacturing apparatus for manufacturing a deoxygenated film for forming a deoxygenated layer of the deoxygenated film laminate will be described.
FIG. 7 is a schematic view of an apparatus for producing a deoxidizing resin film according to the present embodiment.
As shown in FIG. 7, the deoxygenating resin film manufacturing apparatus 30 puts the chip-shaped resin composition 18 through a feeder 31 and melts it at a predetermined temperature, and extrudes it from a T-die 32a into a sheet-like product 33. A take-up device 34 having an extruding machine 32, take-up rollers 34a, 34b for taking up the sheet 33, and a take-up roller 34c for taking up the deoxidized film 35 which is the taken-up sheet. And a temperature controller 36 for adjusting the temperature of the take-up rollers 34a and 34b, and an N ₂ inert atmosphere chamber 37 in which nitrogen gas is supplied into the winding device 34.
In the present embodiment, the take-up device 34 is composed of a take-up roller and a take-up roller. However, the take-up roller 34 and the take-up roller are provided in separate N ₂ inert atmosphere chambers as separate structures. A take-off roller device may be used.

  The chip-shaped resin composition 18 supplied to the extrusion machine 32 is melted at a predetermined temperature, and then extruded from the T die 32a as a sheet-shaped material 33 having a predetermined thickness, while being pulled by take-off rollers 34a and 34b. After being taken to a predetermined thickness, it is taken up by a take-up roller 34c and sealed in a nitrogen purged bag to obtain a product.

In the present invention, the temperature of the take-up roller is controlled when the cerium oxide-based deoxygenated resin composition is formed into a film under an inert gas atmosphere.
Specifically, the temperature of the take-up roller is raised as the filling amount of cerium oxide filled in the resin increases. As a result, the sheet-like material 33 can be taken out without being cut by pulling the extruded sheet-like material 33 in the molten state by the take-up rollers 34a and 34b.
FIG. 8 is a relationship diagram between the cerium oxide filling amount and the temperature of the take-up roller. As shown in FIG. 8, as the filling amount of cerium oxide into the resin increases, the take-off temperature is raised, so that the cutting of the sheet-like material is eliminated. As shown in FIG. 8, as the filling amount of cerium oxide increases, the temperature of the take-up roller is gradually increased from 50 ° C., and a good deoxygenated film can be produced by setting the temperature to 120 ° C. .

  Hereinafter, although one Example for confirming the effect of this invention is described, this invention is not limited to this Example.

[Examples 1 to 8]
As the resin of this example, polypropylene (manufactured by Nippon Polypro Co., Ltd .: trade name “Novatech PP: Model FB3HAT) was used. As the oxygen scavenger, as the cerium oxide reduced powder, CO ₂ coated cerium oxide reduced powder ( The average particle size was 2 μm (maximum particle size: 10 μm) manufactured by Mitsui Mining & Smelting Co., Ltd. The cerium oxide reduced powder was obtained by calcining cerium carbonate at 1100 ° C. for 1 hour in the atmosphere, then at 1000 ° C. in 100% hydrogen. The oxygen absorption amount of this reduced cerium oxide powder was 20 mL / g, and the cerium oxide reduced powder CO ₂ was coated with cerium oxide reduced in a 100% CO ₂ gas atmosphere. The powder was heated from room temperature (10 ° C./min), then reached 300 ° C., held at that temperature for 2 hours, and then allowed to cool naturally.
As a biaxial kneading extruder, a biaxial co-rotating kneading extruder (Berstorf (Germany): “Model ZE40A”, screw length (1340 mm, L / D = 33.5), die: φ5 mm × 5 holes) Was used.
As the strand cooling tank, a water-cooled cooling tank was used, and oxygen-free water (by nitrogen bubbling)) was used as the refrigerant. The oxygen concentration in oxygen-free water was 1 ppm. Resin was charged from the main feeder, cerium oxide reduced powder was charged from the side feeder, and the purge gas in the side feeder was nitrogen.
For the production of deoxidized film, a T-die extruder “Lab Plast Mill” (manufactured by Toyo Seiki Seisakusho: screw length: 1340 mm, φ20 mm, L / D = 25, full flight screw; T die: width 150 mm) Lip width 250 μm).
The feeder portion of the resin composition was nitrogen purge gas, the entire winding device was covered with an acrylic cover, and the inside was purged with N ₂ gas.

The mixing ratio of the resin and the reduced powder of cerium oxide is 1: 4 (Example 1), 1: 3 (Example 2), 1: 2 (Example 3), 1: 1 (Example 4), 2: 1 (Example 5), 3: 1 (Example 6), 4: 1 (Example 7), and 7: 1 (Example 8), the compounding ratio (filling ratio to resin: 20% to 88%) ) Was changed.
Table 1 shows the relationship among the blending ratio, filling rate, and take-up temperature of the reduced cerium oxide powder and the polypropylene resin according to this example.
The kneading preset temperature in the twin-screw kneading extruder was 180 ° C., and the outlet resin temperature was 227 to 257 ° C. In any case, the discharge of the strand was stable and the kneading state was extremely good.
Further, the melting temperature in the extrusion molding machine was 205 ° C., and the outlet resin temperature was 195 ° C.

  A film having a thickness of 50 μm and a film having a thickness of 30 μm according to Examples 1 to 8 were obtained. And the 50-micrometer film of a present Example was able to be set as favorable film formation in any of 20 to 88% of a filling rate. On the other hand, the 30 μm film according to Examples 1 to 7 could be made into a good film at any filling rate of 20 to 80%. In addition, the 88% film according to Example 8 had some holes.

In each Example, since the average particle diameter of cerium oxide was 2 μm and the true specific gravity was relatively high at 6 to 7 g / cm ³ , the resin could be filled with a large amount of cerium oxide.
The blending ratio of iron powder used as a conventional oxygen scavenger to the resin is limited to about 33% in consideration of a hole in film formation (due to a large particle size of 10 μm or more). In the present embodiment, a blending ratio of iron powder or more can be achieved.

  Moreover, since the deoxygenation capacity of cerium oxide is about 20 to 30 mL / g, the deoxygenation capacity (78 mL / g) having approximately the same deoxygenation capacity as iron can be obtained by setting the resin filling to 50% to 80%. An oxygen-based resin composition could be obtained.

  In the case of a conventional oxygen scavenger using iron powder, an alkali halide or alkaline earth metal halide such as sodium chloride, potassium chloride, magnesium chloride, calcium chloride is added as an oxidation accelerator. On the other hand, since the cerium oxide-based oxygen scavenger of the present invention does not add such a material, it does not adversely affect the product contained in the package.

[Examples 9 and 10, Comparative Example 1]
Using the obtained oxygen scavenging film (blending ratio 1: 1 (Example 4)) 35, it was cut into 10 cm square (100 cm ² ) as shown in FIG. An adhesive layer (polyethylene thickness 20 μm) 38 and a barrier layer (PVOH (ethylene-polyvinyl copolymer) 39 having a thickness of 30 μm) 39 cut to the same dimensions are sequentially stacked, and a laminate 40 of a three-layer film is obtained with a laminator. It was.

Furthermore, as shown in FIG. 10, the laminated body 40 was folded in half so that the deoxidation film 35A faced inward, and the three sides were sealed to obtain a bag-like package 41 according to Example 9.
A rubber plate 42 was attached to one side surface of the package 41 (outside, ie, on the surface of the barrier layer 39), and 25 mL of air was injected into the package 41 through the rubber plate 42 using a syringe 43. Next, the oxygen concentration inside the package 41 was measured at regular intervals.

<Oxygen absorption test>
As a measuring device, oxygen concentration was measured using "Zirconia type oxygen concentration meter (model: LC-750F)" manufactured by Toray Engineering Co., Ltd.
The measurement results are shown in FIG.

  As shown by the black circles in FIG. 11, in the package of Example 9, the oxygen inside the package could be reduced to 0% in about 2 days.

As Example 10, was obtained which was operated in the same manner as in Example 9 for the case where not the CO ₂ coating cerium oxide reduction powder. In the package according to Example 10, the oxygen absorbing ability was lowered as shown by the white circles in FIG. As described above, in the cerium oxide reduced powder, when the CO ₂ coating was not performed, the contact with oxygen occurred slightly more than the CO ₂ coating as in the embodiment, and as a result, the oxygen Absorption capacity has been reduced.

On the other hand, in the formulation of Example 4 as Comparative Example 1, when supplying the reduced cerium oxide powder, an inert gas purge is not performed, and a deoxygenated resin composition that does not use oxygen-free water in cooling the strand is obtained. A package was obtained by operating in the same manner as described below, and the test was conducted in the same manner.
As a result, in the case of Comparative Example 1, as shown by the black squares in FIG.
Therefore, an inert gas atmosphere in the supply of cerium oxide reduced powder, more preferably cooling without reducing the oxygen absorption capacity in the cooling of the strands is essential for industrial production in large quantities. It has been found.

  According to the present invention, a cerium oxide-based oxygen scavenger having oxygen defects and a resin are kneaded in a non-oxygen atmosphere using a kneading extruder, and the extrudate is oxygen-free in oxygen-free water or nitrogen or nitrogen-enriched air. A deoxidizing resin composition can be obtained without lowering the oxygen absorption capacity by cutting after cooling without lowering the absorption capacity.

  Accordingly, the deoxygenating resin composition manufacturing apparatus and deoxygenating resin film manufacturing apparatus according to the present invention can manufacture the resin composition and film without reducing the oxygen capacity in the manufacturing process. It is suitable for efficient removal of oxygen when used as a food packaging.

Claims (1)

When extruding a cerium oxide-based deoxygenating resin composition into a sheet-like material, the oxygen is removed while adjusting the temperature of a take-up roller for taking up the sheet-like material and making the winding device a non-oxygen atmosphere. A method for producing a conductive resin film,
A method for producing a deoxygenating resin film, wherein the temperature of the take-up roller is increased as the filling amount of cerium oxide filled in the resin composition is increased .

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