JP2803508B2 - Oxygen absorbent, its production method and oxygen-absorbing composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an oxygen absorbent, a process for producing the same, and an oxygen-absorbing composition.
The present invention relates to a polymer metal complex-based oxygen absorbent having high reactivity even with low partial pressure oxygen and a method for producing the same.

[0002]

2. Description of the Related Art Conventionally, metal cans, glass bottles, various plastic containers and the like have been used as packaging containers.
Deterioration of contents and reduction in flavor due to oxygen remaining in the container and oxygen permeating the container wall have become problems.

[0003] In particular, in a metal can or a glass bottle, oxygen permeation through the container wall is zero, and only oxygen remaining in the container is a problem, whereas in a plastic container, oxygen permeation through the container wall is zero. It occurs in orders that cannot be ignored and poses a problem in the preservability of the contents.

In order to prevent this, in a plastic container, the container wall has a multilayer structure, and at least one of the layers is made of an oxygen-permeable resin such as an ethylene-vinyl alcohol copolymer. I have.

[0005] An oxygen absorber has been used for a long time to remove oxygen in a container. An example of applying the oxygen absorber to the container wall is disclosed in Japanese Patent Publication No. 62-1824. According to the method, a layer formed by mixing a deoxygenating agent containing a reducing substance as a main component with a resin having oxygen permeability and a layer having oxygen gas barrier properties are laminated to form a multilayer structure for packaging.

Japanese Patent Application Laid-Open No. 1-278 according to the proposal of the present inventors.
The 344 discloses an oxygen permeation coefficient at 20 ° C. and 0% RH is ^{10 - 1 2 cc · cm /} cm 2 · sec · cmHg and below 2
A resin composition obtained by blending an organometallic complex of a transition metal with a gas barrier thermoplastic resin having a water adsorption of 0.5% or more at 0 ° C. and 100% RH is used as an intermediate layer. A plastic multilayer container comprising a laminated structure provided with a layer of a thermoplastic resin is described.

[0007]

The complex is characterized in that the transition metal is coordinated to an organic ligand such as a nitrogen-containing base in the form of an ion. It has the advantage of being carried out even at low pressures, but the transition metal complex tends to elute into water when it comes in contact with water, so it is in the form of a resin composition and also has a moisture-resistant thermoplastic There is a restriction on applications in that it must be used in a form sandwiched between resin layers.

In particular, oxygen remaining in the head space of the container or remaining as a result of being dissolved in the contents has a small partial pressure. Therefore, when the transition metal complex is brought into contact with water, It is expected that a very great advantage will be achieved if it can be provided on the inner surface side of the container or the container lid with less tendency to dissolve.

Accordingly, an object of the present invention is to provide a polymer metal complex-based oxygen absorbent which has a small tendency to elute when contacted with water and has remarkably excellent oxygen absorbability, a process for producing the same, and a composition thereof. is there.

[0010]

According to the present invention, a polyether
An oxygen absorbent is provided which comprises a water-insoluble complex obtained by crosslinking a complex of thylene imine and a transition metal with a crosslinking agent reactive to basic nitrogen.

According to the present invention, a step of reacting polyethyleneimine with a water-soluble salt of a transition metal in the presence of water and substantially in the absence of oxygen to form a complex, A reaction with a cross-linking agent in the substantial absence of an oxygen absorber.

In the production method of the present invention, it is preferable to heat-treat the resulting oxygen absorbent in a system substantially free of oxygen at a temperature of 100 ° C. or higher and lower than the decomposition temperature of the polymer.

According to the present invention, there is further provided a crosslinked polyethylene.
An oxygen-absorbing agent comprising an oxygen absorbent comprising a complex of a polymer ligand composed of renimine and a transition metal coordinated to the ligand, and a water-absorbent resin composition having oxygen permeability. A composition is provided. In this composition, the oxygen absorbent and the water-absorbing resin composition are preferably present in a weight ratio of 1:25 to 3: 1.

[0014]

In the present invention, a water-insoluble complex obtained by crosslinking a complex of polyethyleneimine and a transition metal with a crosslinking agent having reactivity with basic nitrogen is used as an oxygen absorbent.

[0015] As already pointed out, complexes of transition metals, transition metals are those having a chemical structure coordinated to organic ligand nitrogenous base in the form of ions, the absorption of oxygen is rapidly,
Moreover, it is effectively performed even when the oxygen partial pressure is low.

In the present invention, in order to suppress the tendency of the transition metal complex to elute in water, a polyether is used as the organic ligand.
Crosslinking is carried out with a crosslinker having reactivity with basic nitrogen while using thylene imine . By this crosslinking reaction, polyethyleneimine becomes a three-dimensionally reticulated structure, its water solubility is suppressed, and transition metal ions are also held in the reticulated ligand cage to suppress water elution tendency. Is done.

[0017] For example, the aqueous solubility of polyethylenimine complexes of transition metals of uncrosslinked (Fe) as iron ion 10 ^- but of the order of ⁴ mol / ml, the polyethyleneimine complexes of transition metal, silane In the case where the coupling agent is crosslinked as a crosslinking agent, the elution amount as iron ions is suppressed to the order of 1/1000 or less (see Example 2 in Examples described later).

In the oxygen absorbent of the present invention, polyethylene
First reacting the min and the transition metal component to form a complex,
Next, it is important to cause a crosslinking agent to act on this complex to cause crosslinking, from the viewpoint of oxygen absorption performance.

FIG. 1 is a cross-sectional view in which polyethyleneimine and iron are first reacted and then cross-linked according to the present invention (marked with ○) (for details, see the examples described later) and polyethyleneimine is cross-linked first. The relationship between the aging and the amount of oxygen absorption was measured for a complex (marked by ●) which was then reacted with iron to form a complex.

According to the results, it is understood that those obtained in the order of complexation / crosslinking exhibit remarkably superior oxygen absorption rates as compared with those obtained in the order of crosslinking / complexation. In addition, the tendency of saturation of oxygen absorption was already exhibited in the case of crosslinking and complexing performed in this order, whereas such tendency was not observed in the case of performing complexing and crosslinking in this order. It is also found that the oxygen absorption capacity is remarkably excellent.

[0021]

The fact that in the oxygen absorbent of the present invention, the complexing and crosslinking are performed in this order to improve the oxygen absorption is found as a phenomenon, and the reason for this is completely unknown. However, in the oxygen absorbent of the present invention,
It is thought that the coordination structure has a high degree of freedom in forming the coordination structure, and a desirable coordination structure is obtained in terms of oxygen absorption.

The oxygen absorbent of the present invention can be used alone, of course, but can also be mixed with a resin and used in the form of a resin composition. In this case, it is preferable to combine with resins having oxygen permeability and water absorbency.
This is advantageous in terms of the oxygen absorption rate, oxygen absorption capacity, and initial rise rate. As shown in the examples described below, when used in the form of a composition with a water-absorbing resin, an oxygen absorption rate that is twice as high as that obtained when a resin having neither oxygen permeability nor absorption can be obtained. .

The oxygen absorbent and the composition of the present invention have a markedly suppressed dissolution property in water, a high oxygen absorption rate and excellent absorption performance even at a low oxygen partial pressure. It is particularly useful for the purpose of absorbing and removing oxygen remaining in the space or in the contents, and can be provided on the inner surface of a crown, cap, can lid, or the like.

[0025]

BEST MODE FOR CARRYING OUT THE INVENTION (Oxygen absorbent and its production)

[0026]

In the present invention, polyethyleneimine is used as a ligand because it contains basic nitrogen at a high concentration .

The transition metal component used in the present invention includes:
Group VIII metal components of the periodic table such as iron, cobalt and nickel are preferable, but other Group I metals such as copper and silver: Group IV metals such as zirconium, Group V of vanadium and chromium VI
Group VII metal components such as manganese. Among these metal components, the cobalt component has a high oxygen absorption rate even in the composite of the present invention, and is particularly suitable for the purpose of the present invention. Another suitable metal component is an iron component.

The complexation reaction between the transition metal component and polyethyleneimine is carried out by reacting a low-valent water-soluble salt of the transition metal with a polyethylene.
The reaction is carried out by reacting renimine in the presence of water and in the substantial absence of oxygen. As the salt, an inorganic acid salt such as a halide or a sulfate, or an organic acid salt such as an acetate is used. The reaction is preferably carried out in an aqueous medium, but can also be carried out in a water-miscible organic solvent such as alcohols and ketones.

The resulting complex may be prepared by any suitable means if necessary.
Can be separated. If it is obtained as a precipitate, it may be separated by a known solid-liquid separation means such as filtration, and in the case of a solution, it is evaporated to dryness, or a non-solvent for the complex is added to the solution. And collect as a precipitate.

The complex of the high-molecular ligand and the transition metal can be supported on the surface of the inorganic carrier, thereby improving the handleability as a powder and dispersing in a resin. Can be significantly improved.

As the inorganic carrier, the BET specific surface area is 50
An inorganic carrier of at least m ² / g, especially at least 100 m ² / g, is used. Silica gel is preferably used as the inorganic carrier, but in addition, silica alumina, various clays, zeolite, talc, glass powder, activated carbon and the like can be used. The method of supporting the complex on the inorganic carrier is not limited to these.For example, an organic group, for example, a vinyl group, an amino group, a haloalkyl group, an epoxy group, or the like is introduced on the carrier surface by a silane coupling agent, a titanate coupling agent, or the like. Then, these functional groups are reacted with a complex comprising a basic nitrogen-containing polymer and a transition metal.

The content of the inorganic carrier is not particularly limited,
It is preferred that the inorganic carrier and the complex are present in a weight ratio of 100: 1 to 5: 2, especially 25: 1 to 5: 1.

The concentration of the transition metal in the polymer metal complex, in terms of the oxygen-absorbing 2.9 × 10 ^{- 3} mol / 100g complex or more, particularly 4.5 × 10 ^- in ² mol / 100g complex concentrations above Is good.

The complex of polyethyleneimine and the transition metal is then crosslinked using a crosslinking agent. As the cross-linking agent, any cross-linking agent having reactivity with basic nitrogen, that is, active hydrogen bonded to the nitrogen can be used. For example, oxirane ring-containing compounds, aldehydes, or silane or titanium-based cups can be used. A ring agent or the like is used.

Examples of the oxirane ring-containing compound, epichlorohydrin is preferably used, Porigurishiji other
For example, a liquid epoxy resin derived from chloroethers , polyglycidyl esters , vinylcyclohexene oxide, butadiene dioxide, epichlorohydrin and bisphenols may be used.

As the aldehyde, formaldehyde (paraformaldehyde), glutaraldehyde and the like can be used. In addition, a di- to polymethylol compound which is a reaction product of an aldehyde and a phenol, urea or amino can be used. Hexamethylene diisocyanate can be used as the isocyanate compound.

As the silane coupling agent, for example, a compound represented by the formula

Embedded image In the formula, R is a halogen group, an isocyanate group, a vinyl group,
Represents a functional group such as an amino group, an imino group, a mercapto group, a glycidyl group or an alkyl group having the same, X represents a hydrolyzable group, for example, a lower alkoxy group or a halogen atom, and Y represents an alkyl group or a group X. Express.
In particular, vinyl silanes such as vinyl ethoxy silane and vinyl trichloro silane; amino silanes such as amino propyl triethoxy silane; epoxy silanes such as γ-glycidoxy propyl silane are used. As the titanium-based coupling agent, in the above [Chemical formula 1],
A compound having a similar structure is used except that Si is replaced by Ti.

These crosslinking agents may be reacted with the polymer metal complex in such an amount that the complex becomes substantially insoluble in water, and the amount varies depending on the molecular weight of the crosslinking agent. 1 to 400 parts by weight, especially 5 to 2
A range of 00 parts by weight is suitable. The reaction is easily carried out by dissolving the crosslinking agent in a suitable solvent and allowing the polymer to act on the polymer metal complex at a temperature of room temperature to 200 ° C. Of course,
This crosslinking reaction is preferably performed in the absence of oxygen, for example, in the presence of an inert gas such as nitrogen. Other crosslinking methods
Radical generators such as peroxides, and high
An energy source may be used.

(Composition) The oxygen absorbent of the present invention can be used by blending it in a resin or rubber. However, from the viewpoint of improving the oxygen absorption rate, the oxygen absorbent is used in combination with a water-absorbing resin composition. It is preferred to use. Specific examples of the water-absorbing resin composition include the following, which are added to pure water at 20 ° C. based on a JIS standard test method.
It is desirable that the rate of weight increase when immersed for 1 hour or more is 1% or more, and particularly 2.0% or more in practice.

The water-absorbing substance is preferably a polymer in order to suppress dissolution, and from the viewpoint of accelerating the oxygen absorption reaction, polyvinyl alcohol, methylcellulose, ethylcellulose, hydroxypropylmethylcellulose, hydroxyethylcellulose, carboxymethylcellulose, etc. Cellulose derivative, partially saponified polyvinyl acetate, polyvinyl methyl ether, polyacrylic acid, polymethacrylic acid, vinyl methyl ether / maleic anhydride copolymer, polyvinylpyrrolidone , acrylamide / acrylate copolymer, acrylamide / methylene Bisacrylamide copolymer partially saponified, vinyl acetate / methyl acrylate copolymer saponified, polyoxyethylene compound, polystyrenesulfonic acid, poly-2
-Acrylamide-2-methylpropanesulfonic acid, ethylene-vinyl alcohol copolymer, and hydrophilic polymer compounds such as gelatin, modified casein, modified starch, sodium alginate, tragacanth rubber, or a mixture of these and a thermoplastic resin Is preferred.

In the composition of the present invention, the oxygen absorbent and the water-absorbing resin composition are preferably used in a weight ratio of 1:25 to 3: 1, particularly 1:10 to 2: 1, based on two components. . When the amount of the water-absorbing resin is less than the above range, the effect of promoting oxygen absorption is not sufficient, while when it is more than the above range, water resistance tends to be unsatisfactory.

The oxygen absorbing agent can be used in combination with other accelerators known per se for promoting the oxygen absorbing action. As such an accelerator, an electron donating substance, a solid base and the like are known. As these substances, water-insoluble substances are desirable from the viewpoint of the flavor retention and sanitary properties of the contents, for example, zinc oxide, magnesium carbonate, silicate, anion exchange resin, zeolite, melamine resin,
Urea resins, ammonia resole resins, and the like can be given. These accelerators are used in an amount of 0.1 to 5 parts per 100 parts by weight of the oxygen absorbent.
It can be used in parts by weight.

(Use) The oxygen absorbent and the composition of the present invention are in the form of powder, granules, sheets, or the like, and are made of a resin film, paper, woven fabric, nonwoven fabric, or a laminate thereof having oxygen permeability. And can be used for oxygen absorption in the sealed package.

The oxygen absorbent or its composition of the present invention is preferably incorporated into a resin or rubber for forming a liner or gasket or for forming a coating, and then used for absorbing residual oxygen in a package.

As the liner or the polymer for forming the gasket or the packing, known resins or rubbers having appropriate elasticity and cushioning property, particularly soft vinyl chloride resin, low-density polyethylene, ethylene-vinyl acetate, etc. Polymer, low density polyethylene / ethylene-vinyl alcohol copolymer blend, ethylene-propylene copolymer, thermoplastic styrene-butadiene-styrene block copolymer, thermoplastic styrene-isoprene-styrene copolymer, ethylene-propylene Rubber, ethylene-propylene-non-conjugated diene rubber, styrene-butadiene rubber, nitrile-butadiene rubber, butyl rubber, natural rubber, polybutadiene, chloroprene rubber,
Examples include polyurethane, acrylic rubber or elastomer, and silicone rubber. Of these, low-density polyethylene, ethylene / propylene copolymer rubber, plastisol of vinyl chloride resin, styrene-butadiene rubber (SBR), especially solvent type SBR, etc.
Suitable for container liner because of excellent processability. These can be used alone or in combination of two or more as needed. In these resins or elastomers, a resin compounding agent known per se, for example, a plasticizer, a filler, a colorant, a heat stabilizer, a foaming agent, a crosslinking agent and the like can be compounded according to a known formulation.

The oxygen absorbent is preferably used in these polymers in an amount of 5 to 400 parts by weight, particularly 10 to 100 parts by weight, per 100 parts by weight of the polymer.

The application of the resin composition to the inner surface of the container lid such as a cap, a crown, a can lid, etc. is performed by a means known per se.
For example, when a resin melt is used, a method in which the oxygen-absorbing compound-containing resin is applied to the inside of the container lid in the form of a molten lump and pressed to form a liner, or the compounded resin is formed into a packing outside the container lid, and A method of fitting or adhering to a cap or the like is adopted. In the case of a plastisol, a solution or a latex, a mixture obtained by adding an oxygen absorbent to the plastisol, a solution or a latex is applied by means such as a spin corner, and gelled or dried by heating to obtain a liner or a gasket.

Furthermore, it is also possible to mix it in a solution of a coating resin which is a phenol resin, an epoxy resin, an acrylic resin or a mixture thereof and use it as a coating.

Instead of dispersing the oxygen absorbent in the polymer, a sheet of the oxygen absorbent is produced by using a polymer as a binder in the powder of the oxygen absorbent, and this is used as a container lid. Etc. can also be applied. In this case, the amount of the polymer used per oxygen absorbent may be as small as 2 to 50% by weight.

[0051]

The present invention will be described with reference to the following examples. Example 1 Polyethyleneimine (molecular weight 10,000) 1 in a nitrogen atmosphere
To 0 g, 33 ml of a 1 M aqueous solution of cobalt chloride was added, and 54.9 g of γ-glycidoxypropyltrimethoxysilane was further added with stirring. The obtained jelly-like substance was added to 110
C. to obtain a crosslinked product of a polymer metal complex. The polymer metal complex portion in the crosslinked product was 21 wt% based on the total weight.
%. 0.3 g of the crosslinked polymer metal complex is put in an aluminum foil / polyethylene laminate bag together with 0.3 g of water, heat-sealed so that the air volume in the bag becomes 100 ml, and stored at room temperature. Then, the internal oxygen concentration was measured by a gas chromatograph to determine the amount of oxygen absorbed. Similarly, the change in the amount of oxygen was measured using an uncrosslinked polymer metal complex. The results are shown in Table 1.

[0052]

[Table 1] The absorption amount of the product of the present invention was about 0.2 with respect to the oxygen absorption amount of the uncrosslinked product, and the polymer metal complex portion in the crosslinked product was 21 wt%. It can be seen that the absorption capacity is not impaired.

Example 2 Polyethyleneimine (molecular weight 10,000) 1 under a nitrogen atmosphere
To 0 g, 38.8 ml of a 1 M aqueous solution of ferrous chloride is added and stirred thoroughly. Next, 54.9 g of γ-glycidoxypropyltrimethoxysilane was added, and the produced jelly-like substance was heated to 200 ° C. to obtain an insoluble polymer metal complex (product of the present invention). In a nitrogen atmosphere, 10 g of polyethyleneimine and 38.8 ml of water were mixed, and then, while stirring, 54.9 gamma-glycidoxypropyltrimethoxysilane.
g was added and stirred. The produced jelly-like substance was heated to remove water, and a gel of polyethyleneimine was obtained. 10 g of this gel was added to 100 ml of a 0.5 M aqueous ferrous chloride solution, and the mixture was sufficiently stirred, filtered, washed and dried. All of these operations were performed in a nitrogen atmosphere (control). The iron content, oxygen absorption amount, and iron elution amount of each of the product of the present invention and the control product were measured. The results are shown in Table 2.

[0054]

[Table 2] (1) After 2 days (2) A 20 wt% aqueous solution, and the amount of iron in the solution after 2 days at room temperature As is clear from the results, the method of forming a crosslinked structure after synthesizing a polymer complex is to synthesize a crosslinked structure. It is superior to the method of coordinating a metal and then forming a complex.

Example 3 A crosslinked product of a polymer metal complex prepared in the same manner as in Example 1 was stored in air for a certain period of time, and then subjected to a heat treatment to observe changes in oxygen absorption performance. By storage in air, there was a 50% deactivation of the oxygen absorption performance immediately after synthesis. The heat treatment conditions were 200 ° C. for 30 minutes in air and 200 ° C. for 30 minutes in nitrogen.

[0056]

[Table 3] (1) After 40 hours at room temperature It can be seen that the oxygen absorption capacity changes depending on the processing conditions.

Example 4 A gel of a polymer metal complex to which various metals were coordinated was prepared in the same manner as in Example 1. The metal ions used were Fe ^{2 +} ,
Co ^{2 +} , Cu ^{2 +} , Mn ^{2 +} , Mg ^{2 +} , Ag ⁺ , K
⁺ , Al ^{3 +} . The oxygen absorption capacity was measured in the same manner. The absorption after 3 days is Fe ^{2 +} Complex gelation product 7.
4 ml / g, Co ^{2 +} : 5.7 ml, Mn ^{2 +} : 2.3
ml, Cu ^{2 +} : 1.7 ml, and the gelled polymer metal complex made of another metal showed almost no oxygen absorption performance.

Example 5 An aqueous cobalt chloride solution was used as a metal salt, and polyethyleneimine, sodium polyacrylate, polyvinyl alcohol, and polyethylene glycol, which are considered to have metal coordination properties, were used as ligands. A gelled metal complex was prepared. Polyethyleneimine and sodium polyacrylate formed a complex, and only polyethyleneimine showed oxygen absorption. It was found that the nitrogen-containing polymer exhibited good performance.

Example 6 Polyethyleneimine (molecular weight 10,000) 6 in a nitrogen atmosphere
To 0 g, 250 g of a 20% aqueous solution of ferrous chloride tetrahydrate was added. While sufficiently stirring, 330 g of γ-glycidoxypropyltrimethoxysilane was added, and the produced jelly-like substance was heated to obtain a gelled polymer metal complex. After grinding, low-density polyethylene: 9 polyvinyl alcohol
The mixture was mixed with a 5: 5 resin composition and pelletized (the product of the present invention). The pellet was sealed together with a small amount of water in an oxygen-impermeable aluminum / polyethylene laminate bag, and heat-sealed so that the air volume was constant. It was stored at room temperature, and after a certain period of time, the air composition in the bag was examined by gas chromatography. Further, a resin composition containing a gelled polymer metal complex using only low-density polyethylene as a resin (Control 1) and an ethylene-vinyl alcohol copolymer (ethylene content: 32%, saponification degree 99) as a resin (6 mol%) to prepare a resin composition (Control 2) containing a gelled polymer metal complex, and the oxygen absorption capacity was measured in the same manner. The results are shown in Table 4. The amount of gelled polymer metal complex per unit weight is reduced by adding it to the resin, so the absolute absorption amount is reduced.However, the absorption rate is increased by mixing the resin with a resin that has both oxygen permeability and moisture absorption. And the reduction in the amount of absorption per unit weight of pellets can be considerably compensated for. On the other hand, a resin blended with a resin having oxygen permeability but not absorbing water (Control 1) and a resin blended with water absorbing but low oxygen permeability (Control 2) It does not show absorption performance corresponding to the amount of the gelled metal complex.

[0060]

[Table 4]

Example 7 Polyethyleneimine (molecular weight 10,000) 1 in a nitrogen atmosphere
To 0 g, 33 ml of a 1 M aqueous solution of cobalt chloride was added, and 54.9 g of γ-glycidoxypropyltrimethoxysilane was further added with stirring. The surface area is 400m ² / g
Was added and heated at 110 ° C. The product was pulverized with a ball mill to obtain a crosslinked product of a polymer metal complex held on an inorganic carrier. The resin was mixed in a resin made of a polyvinyl alcohol / polyethylene mixture so as to have a concentration of 30% by weight and pelletized. The oxygen absorption amount of the pellet was measured by the method of Example 1. 0.6 ml of O ₂ was absorbed per gram of pellet. Example 8 A crosslinked polymer metal complex was prepared by the method of Example 1,
After grinding with a ball mill in a stream of air, the epoxy-pheno
The mixture was mixed with a polyester-based paint (solid content: 28%) by 65 phr.
Completely epoxy phenolic coating, including the cut edge
On one side of a coated aluminum plate coated with
Apply complex paint and bake at 200 ° C for 10 minutes to form complex
A test piece having a compound coating film was obtained. Application amount of complex compound paint
Was 1.3 g / dm ² . According to the method of Example 1
The amount of oxygen absorption was measured. After 5 days, 2.6 ml / coating
It had absorbed 1 g of oxygen.

[0062]

According to the present invention, a polyester is used as a ligand.
After forming a complex with a transition metal using renimine ,
By cross-linking this with a cross-linking agent, solubility in water could be suppressed, and an oxygen absorbent having a large oxygen absorption rate and oxygen absorption capacity could be obtained. By using this oxygen absorbent together with the water-absorbing resin, a particularly high oxygen absorption rate can be obtained.

The oxygen absorbent of the present invention has a high oxygen absorption rate, is excellent in absorption performance even at a low oxygen partial pressure, and has a low tendency to dissolve in water. Particularly suitable for use in absorbing oxygen remaining therein.

[Brief description of the drawings]

FIG. 1 shows a reaction in which polyethyleneimine and iron are first reacted and then crosslinked according to the present invention (marked with ○) (for details, see Examples), and polyethyleneimine is first crosslinked and then iron is reacted. It is the graph which measured the relationship between time and oxygen absorption amount about what was made into the complex (marked by *).

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁶ , DB name) C08J 3/24 C08F 8/42 C09K 15/00

Claims (12)

(57) [Claims] 1. An oxygen absorbent comprising a water-insoluble complex obtained by crosslinking a complex of polyethyleneimine and a transition metal with a crosslinking agent having a reactivity with basic nitrogen. 2. The transition metal is 2.9 × 10 ⁻³ mol / 10.
The oxygen absorbent according to claim 1, which is contained in a concentration of 0 g or more of the complex. 3. The oxygen absorbent according to claim 1, wherein the transition metal is iron, cobalt, copper or manganese. 4. The oxygen absorbent according to claim 1, wherein the crosslinking agent is an oxirane ring-containing compound, an aldehyde, an alkyl halide, an isocyanate compound, or a silane or titanium-based coupling agent. 5. The oxygen absorbent according to claim 1, wherein the water-insoluble complex is supported on an inorganic carrier. 6. A BET having an inorganic carrier of 50 m ² / g or more.
The oxygen absorbent according to claim 5 , which has a specific surface area. 7. The oxygen absorbent according to claim 5 , wherein the inorganic carrier is silica gel. 8. The oxygen absorbent according to claim 5 , wherein the water-insoluble complex and the inorganic carrier holding the water-insoluble complex are present in a weight ratio of 1:25 to 3: 1. 9. A step of reacting polyethyleneimine with a salt of a transition metal in the presence of a solvent and in the substantial absence of oxygen to form a complex; A method for producing an oxygen absorbent, characterized by reacting the oxygen absorbent with a crosslinking agent. 10. The method for producing an oxygen absorbent according to claim 9 , wherein the produced oxygen absorbent is heat-treated in a system substantially free of oxygen at a temperature of 100 ° C. or higher and lower than the decomposition temperature of the polymer. 11. An oxygen absorbent comprising a polymer ligand comprising a crosslinked polyethyleneimine and a complex of a transition metal coordinated to the ligand, and a water-absorbent resin composition having oxygen permeability. An oxygen-absorbing composition characterized by comprising: 12. water-absorbing resin composition having an oxygen absorber and the oxygen permeability and 1:25 to 3: The composition of claim 11 present in a weight ratio.