KR101466821B1

KR101466821B1 - Oxygen Absorbing Resin Composition For Gasket Of Bottle Cap

Info

Publication number: KR101466821B1
Application number: KR20140089124A
Authority: KR
Inventors: 민동훈
Original assignee: 삼화화학공업주식회사
Priority date: 2014-07-15
Filing date: 2014-07-15
Publication date: 2014-11-28
Also published as: WO2016010211A1; CN105593282A; JP2016532753A

Abstract

60 to 98% by weight of a base resin made of a thermoplastic resin; 0.1 to 20% by weight of a water absorbent resin; 1 to 20% by weight of an oxygen absorber; And 0.1 to 5% by weight of a blowing agent. The oxygen absorbing resin composition according to the present invention has a high oxygen absorption rate and can produce a bottle cap gasket so that oxygen existing in the head space of the bottle can be removed at a high rate to prevent the deterioration of the product contained in the bottle. Accordingly, the gasket can be usefully used for manufacturing the bottle cap provided with the gasket.

Description

Technical Field [0001] The present invention relates to an oxygen absorbing resin composition for a gasket,

More particularly, the present invention relates to an oxygen absorbing resin composition suitable for use as a bottle cap gasket, and more particularly, to an oxygen absorbing resin composition suitable for use as a bottle cap gasket, To an oxygen absorbing resin composition for a bottle cap gasket which can prevent the deterioration of a product contained in a bottle.

Drinks, drinks, etc. are produced and distributed in containers such as glass bottles or plastic bottles. In such a container, oxygen remains in the head space between the contents and the lid, and the contents of the container may be altered by the oxygen remaining in the head space.

Patent Publication No. 10-2005-0119543 (published Dec. 21, 2005) discloses a resin composition capable of absorbing oxygen and absorbing moisture. (EVOH), polyvinyl alcohol (PVA), SAP (Super Absorbent Polymer), PEO (Poly Ethylene Oxide) and calcium carbonate (CaCO ₃ ), which are transition metal salts to the thermoplastic olefin resin. Is mixed with a water absorbent selected from the group consisting of

Patent Registration No. 10-0953352 (registered on Apr. 09, 2010) discloses an oxygen-absorbing resin composition and an oxygen-absorbing container cap and an oxygen-absorbing container closure using the same. In order to solve the problems that occur when an oxygen absorbent having high oxygen absorbability but low compatibility with a base resin is contained, this oxygen absorbent contains a particle size of not more than 1000 mu m of not less than 20% The absorbent is dispersed and compounded in a proportion of 20% or less based on the base resin. The composition of this patent also comprises an absorbent material which is a fatty acid ester and has an HLB value between 4.3 and 10 or less.

In addition, Japanese Patent Application Laid-Open No. 1994-0014098 (published on July 16, 1994), Japanese Patent Application Laid-open No. 10-2007-0118283 (published on December 14, 2007) and Utility Model Registration No. 20-0421312 05. Registration) discloses an oxygen-absorbing container cap.

According to the above-mentioned conventional techniques, it is possible to prevent the contents from being deteriorated by removing oxygen remaining in the head space between the contents and the lid in a container such as a glass bottle or a plastic bottle, An improvement in oxygen absorption performance is required.

Accordingly, it is an object of the present invention to provide a gasket which is capable of preventing deterioration of a product embedded in a bottle by rapidly removing oxygen existing in a head space of the bottle when the bottle cap gasket is manufactured with high oxygen absorption rate To provide an oxygen absorbing resin composition, particularly an oxygen absorbing resin composition for a bottle cap gasket.

It is also an object of the present invention to provide a bottle cap provided with an oxygen-absorbing product made by such a composition, especially a gasket made by such a composition.

According to an aspect of the present invention, there is provided an oxygen absorbing resin composition according to the present invention which comprises 60 to 98% by weight of a base resin made of a thermoplastic resin; 0.1 to 20% by weight of a water absorbent resin; 1 to 20% by weight of an oxygen absorber; And 0.1 to 5% by weight of a blowing agent.

The oxygen absorbing resin composition may further comprise 0.1 to 20% by weight of the porous material.

Further, according to another aspect of the present invention, the oxygen absorbing resin composition of the present invention comprises 60 to 98% by weight of a base resin made of a thermoplastic resin; 0.1 to 20% by weight of a water absorbent resin; 1 to 20% by weight of an oxygen absorber; And 0.1 to 20% by weight of a porous material.

The oxygen absorber is preferably a compound having reducibility, and the oxygen absorber is preferably sodium sulfite or potassium sulfite.

The particle size of the oxygen absorbent is preferably 1 to 900 nm.

The water absorbent resin is preferably an ethylene vinyl alcohol copolymer (EVOH).

The porous material is preferably silica.

The base resin preferably comprises a polyolefin resin and a rubber component, and the weight ratio of the polyolefin resin to the rubber component is preferably 2: 1 to 1: 2.

The rubber component is a mixture of an alpha olefin rubber and a styrene butadiene rubber, and the weight ratio of the alpha olefin rubber to the styrene butadiene rubber is preferably 2: 1 to 1: 2.

The present invention also provides an oxygen absorbing product produced by the oxygen absorbing resin composition described above. The product may be, in particular, a bottle cap provided with a gasket produced by the oxygen-absorbing resin composition.

The oxygen absorbing resin composition according to the present invention has a high oxygen absorption rate and can produce a bottle cap gasket so that oxygen existing in the head space of the bottle can be removed at a high rate to prevent the deterioration of the product contained in the bottle. Accordingly, the gasket can be usefully used for manufacturing the bottle cap provided with the gasket.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a view schematically showing a detailed structure of a bottle cap gasket manufactured by an oxygen absorbing resin composition according to the prior art. FIG.
2 is a view schematically showing the detailed structure of a bottle cap gasket produced by the oxygen absorbing resin composition according to the present invention.

Hereinafter, the present invention will be described in detail.

According to one embodiment, the oxygen absorbing resin composition of the present invention comprises 60 to 98% by weight of a base resin made of a thermoplastic resin; 0.1 to 20% by weight of a water absorbent resin; 1 to 20% by weight of an oxygen absorber; And 0.1 to 5% by weight of a blowing agent. The oxygen absorbing resin composition may further comprise 0.1 to 20% by weight of a porous material.

According to another aspect, the oxygen absorbing resin composition of the present invention comprises 60 to 98% by weight of a base resin made of a thermoplastic resin; 0.1 to 20% by weight of a water absorbent resin; 1 to 20% by weight of an oxygen absorber; And 0.1 to 20% by weight of a porous material.

In the oxygen absorbing resin composition of the present invention, the oxygen absorbing agent is oxidized when oxygen is encountered because of its strong property to be oxidized. Thus, by manufacturing the gasket attached to the cap with the oxygen absorbing resin composition of the present invention, it is possible to remove the oxygen present in the head space of the bottle and prevent the deterioration of the product contained in the bottle.

1 is a view schematically showing the detailed structure of a bottle cap gasket 10 manufactured by an oxygen absorbing resin composition according to the prior art. However, the oxygen absorbent 200 is dispersed in a base resin such as a thermoplastic resin, as shown in Fig. This base resin forms the substrate, i.e. matrix 100, in the cap seal 10.

Although the base resin does not have perfect oxygen barrier properties, the oxidation reaction of the oxygen absorbent is somewhat disturbed by the base resin because it has some degree of oxygen barrier property. Therefore, in the bottle cap gasket having a structure in which the oxygen absorbent is dispersed in the base resin, the oxygen absorption performance is insufficient.

To overcome this structural problem, prior art techniques have incorporated a water absorbent, such as ethylene vinyl alcohol copolymer, in addition to the oxygen absorbent into the base resin. Here, the water absorbing agent can be uniformly mixed with the base resin. That is, the water absorbent becomes the same phase as the base resin. On the other hand, the oxygen absorbing agent is only dispersed in the base resin to form different phases. The bottle cap gasket 10 having such a structure has a structure in which the base resin and the water absorbent resin are uniformly mixed to form the matrix 100 as shown in FIG. 1 and the oxygen absorbent 200 is uniformly dispersed therein .

In the gasket 10 having such a structure, the oxygen absorbent 200 is mainly oxidized by an indirect reaction by the water absorbent rather than by directly reacting with the oxygen. This indirect oxidation reaction begins by the absorption of moisture by the water absorbent. Here, the water absorbed by the water absorbent is water rather than liquid, and the water vapor present in the head space is absorbed by the water absorbent. This water absorption takes precedence over the surface of the gasket. Next, the moisture absorbed by the water absorbent at the surface of the gasket can be transmitted or moved along a network formed by the water absorbent in the matrix formed by the base resin and the water absorbent resin together. The moisture thus transferred can be brought into contact with the oxygen absorbent. Then, the oxygen absorbent is oxidized by moisture and water is changed into hydrogen. Hydrogen generated from moisture chemically reacts with the oxygen present in the head space to generate moisture again. Thus, it can be seen that in this overall reaction, the water only serves to catalyze the oxidation of the oxygen absorbent.

As for the indirect oxidation method of the oxidizing absorbent, it is essential that the moisture is absorbed by the water absorbing agent and the water is moved by the water absorbent network, and if the process is performed quickly, the oxygen absorbing performance is improved do.

The present invention has developed a factor that makes such a process faster, which is to improve the oxidation rate of the oxidized absorbent by shortening the water movement path by the water absorbent network.

2 is a view schematically showing the detailed structure of a bottle cap gasket produced by the oxygen absorbing resin composition according to the present invention.

The first method of shortening the water movement path by the water absorbent network is to include a foaming agent in the coral absorbent resin composition of the present invention so that a bottle cap gasket produced by the composition is foamed and formed into a structure having pores therein. 2, a bottle cap gasket 10 manufactured by the oxygen absorbing resin composition of the present invention has pores 300 formed in a matrix 100 composed of a base resin and a water absorbent resin, and the matrix 100 The oxygen absorbent 200 is uniformly dispersed. In the bottle cap gasket 10 having such a structure, the pores 300 are communicated to the outside, specifically, the head space, because the pores 300 are not closed but open. Thus, such pores 300 are filled with oxygen and moisture.

In FIG. 2, the oxygen absorbent 200 and the pores 300 are somewhat exaggerated, wherein the pores 300 are formed substantially uniformly in the matrix 100. Therefore, the distance from the oxygen absorbent 200 to the water, that is, the path is shortened not only on the surface of the gasket 10 but also inside. This means that moisture absorption by the water absorbent is actively performed not only on the surface of the gasket 10 but also inside the gasket 10 and also means that the moisture absorbent absorbs water Means that the oxygen absorbing agent is shortened in time until the oxygen absorbent is oxidized by moisture. In other words, it means that the rate of oxygen absorption by the oxygen absorbent is improved.

In the above description, pores 300 due to foaming are formed in the matrix 100, but the same effect can be obtained by a structure in which porous materials such as silica are uniformly dispersed in a phase different from that of the matrix 100 have. The porous material has many pores therein. Accordingly, the porous material can not only accelerate the water absorption by the water absorbent by including oxygen and moisture therein as well as the pores 300 formed by foaming in the gasket for a cap manufactured by the oxygen absorbing resin composition of the present invention It is possible to shorten the movement path to the oxygen absorbent after moisture absorption to improve the oxygen absorption rate.

In the present invention, when the porous material is included together with the pores 300 formed by foaming, the synergistic effect of the two is exhibited to further improve the oxygen absorption rate.

In order for the oxygen absorbing resin composition of the present invention to perform such action, a thermoplastic resin is used as the base resin. The thermoplastic resin used in the present invention is not particularly limited as long as it is a thermoplastic resin generally used for producing a bottle cap gasket, and polyolefin resins such as polyethylene and polypropylene are preferably used.

The base resin can be formed only of the polyolefin resin described above, but it is preferable to include a rubber component in addition to the polyolefin resin in order to increase the sealing ability by the elasticity of the gasket. When the rubber component is contained in the base resin, the weight ratio of the polyolefin resin to the rubber component in the base resin is preferably in the range of 2: 1 to 1: 2.

As the rubber component, synthetic rubber generally known can be used singly, but it is more preferable to use a mixture of an alpha olefin rubber and a styrene butadiene rubber. It is also preferred to use a mixture of an alpha olefin rubber and a styrene-ethylene-butylene-styrene copolymer (SEBS) rubber. When a mixture is used as the rubber component, the weight ratio of the alpha olefin rubber to the styrene butadiene rubber or SEBS rubber in the rubber component is preferably from 2: 1 to 1: 2.

Examples of the alpha olefin rubber include isobutene-isoprene rubber, butyl rubber, ethylene-propylene rubber such as EPM and EPDM, and the like.

In the present invention, the water absorbent resin may be a commonly known water absorbent if it has a water absorbing function, but it is preferably an ethylene vinyl alcohol copolymer (EVOH).

The oxygen absorber in the present invention is not particularly limited as long as it is a compound having a reducing property. Specifically, sodium sulfite, potassium sulfite, reducing iron powder, reducing tin powder, reducing zinc powder, ferrous oxide, iron carbide, silicon iron, carbonyl iron, iron hydroxide and the like can be used. Among them, sodium sulfite or potassium sulfite can be preferably used. The oxygen absorbing agent is dispersed in the form of powder not mixed with the matrix resin 100. In order to improve uniform dispersion and oxygen absorption performance, the particle size of the oxygen absorbing agent is in the range of 1 to 900 nm .

The foaming agent in the present invention is not particularly limited as long as it is used for foaming the polymer resin. One embodiment of the present invention provides an example using citric acid and sodium bicarbonate as a blowing agent.

In the present invention, the porous material is not particularly limited as long as it contains pores therein and has a powder phase. The porous material is not mixed with the matrix resin in the composition of the present invention and is only dispersed. The porous material that can be particularly preferably used in the present invention is porous silica.

In the present invention, it is preferable that the component ratios of the respective components have the ranges described. If a component ratio of an ingredient is added in an amount smaller than the stated range, it is difficult to achieve the performance desired by the ingredient. On the contrary, if a component ratio of a certain component is added in an amount larger than the range described, the performance to be obtained by the component can be sufficiently achieved, but the amount of the other components becomes small, so that it is difficult to achieve a harmonization of the overall physical properties.

Hereinafter, the present invention will be described in more detail with reference to examples. It should be understood, however, that the scope of the present invention is not limited to the following examples, which are merely illustrative of the present invention.

Example

Example 1 to 3

From the oxygen absorbing resin composition formed according to the composition ratio in the following table, a product which can be used as a gasket for a cap was prepared.

division Characteristic Example 1
(Parts by weight) Example 2
(Parts by weight) Example 3
(Parts by weight) LDPE Specific gravity = 0.915, melting point = 105 DEG C, hardness = 99A 45.00 45.00 45.00 Alpha olefin rubber Specific gravity = 0.870, melting point = 58 DEG C, hardness = 70A 22.85 22.45 22.40 Styrene butadiene rubber Specific gravity = 0.94, hardness = 70 A, styrene content: 31 wt% 22.85 22.45 22.40 The oxygen absorbent (Na ₂ SO ₃ ) 7.00 7.00 7.00 Water-absorbing resin (EVOH) 2.00 2.00 2.00 Antioxidant 1010 company 0.10 0.10 0.10 blowing agent citric acid + sodium bicarbonate 0.20 0.20 Porous silica Average Particle Size: 2 micrometers 1.00 1.00

Oxygen absorption rate measurement

The oxygen absorption rate was measured for the products of the above examples. In order to measure the oxygen absorption rate, the specimens prepared according to the above-mentioned Examples were prepared. The specimens were thermally pressurized to a thickness of 0.4 mm or less. Specifically, 600 mg of a pellet type sample for measuring the oxygen absorption rate was applied to a specimen manufacturing machine, heated and held at 180 캜 for 15 minutes, and a sheet of 0.4 mm or less was produced by using a press press.

Meanwhile, a 20 ml glass bottle (Bayer bottle for injection solution) was prepared. As a stopper for the injection solution, an inner stopper made of butyl rubber which can seal the container and an aluminum stopper were prepared. Standard bottles with a diameter of 20 mm were used.

In addition, a crimper for a 20 mm diameter was prepared as a sealing mechanism for sealing an aluminum plug to a glass bottle.

Next, 1 ml of water (H ₂ O) was administered into a 20 ml container. In this case, distilled water was used to eliminate test errors due to impurities.

An oxygen-absorbing liner specimen was placed in the vessel to which water was administered. At this time, the specimen was fixed to the upper part of the inner side of the plug in the container so as not to contact with water. In the fixation method, the inner stopper of the specimen and the butyl rubber material was fixed using a pin.

After sealing the inner stopper with the sample fixed to the container, the aluminum stopper was completely sealed with a crimper. The sealed container was pretreated at a constant temperature of 50 캜 for a certain period of time.

For comparison, glass bottles without specimens were treated under the same conditions, and vials treated with known specimens were treated under the same conditions. Here, the known product specimen is the same as Examples 1 to 3, but refers to a product containing no foaming agent and porous silica.

Oxygen uptake was calculated by measuring the residual oxygen content in the glass bottle after a certain period of time.

The oxygen concentration in the vessel treated as described above was measured by gas chromatography (GC). The GC measurement conditions were as follows.

- Used equipment name: Agilent 6890 (Manufacturer: Agilent)

- GC analysis conditions

* Injector temperature: 210 ℃

* Injection volume: 0.1 ml

* Oven: 40 ℃ constant temperature

* Detector: TCD (Temperature: 240 ℃)

Column: Pack Column (Carboxen 1004)

* Mobile phase: He (helium)

* Flow rate: sample analysis pre-treated at 24 ml / min

The oxygen uptake was calculated by the following equation by measuring the difference between the oxygen content in the blank container (glass bottle without specimen) and the oxygen content in the container into which the specimen was placed.

Oxygen absorption rate = (A - B) x 100 / A

Where A is the amount of oxygen in the blank vessel and B is the amount of oxygen in the sample vessel.

The results of the oxygen absorption rate are shown in Table 2.

division
Oxygen content (%) After 12 hours After 1 day 3 days later Seven days After 15 days 30 days later Psalterless bottle 20.20 20.10 20.20 20.10 20.10 20.10 Notice Product Piece 19.20 18.70 17.50 15.80 14.90 14.50 Example 1 Product 17.30 16.50 16.10 14.90 14.70 14.50 Example 2 Product 18.10 17.50 16.80 15.10 14.80 14.50 Example 3 Product 16.10 15.30 14.70 14.50 14.50 14.50

As shown in Table 2, it was confirmed that the product of Example according to the present invention can absorb oxygen at a higher rate than the known product. Among the products of the examples of the present invention, it was confirmed that the product of Example 3 containing pores and foamed by the foaming agent and containing porous silica showed the highest rate of oxygen absorption. This is a result of the effect of the foamed pores and the effect of the porous silica superimposed on each other.

On the other hand, it was confirmed that the effect of the foaming pores on the oxygen absorption rate (Example 1) was superior to that of the porous silica (Example 2).

10: gasket 100: matrix
200: oxygen absorbent 300: porous or porous material

Claims

60 to 98% by weight of a base resin made of a thermoplastic resin; 0.1 to 20% by weight of a water absorbent resin; 1 to 20% by weight of an oxygen absorber; And 0.1 to 5% by weight of a blowing agent,
Wherein the base resin and the water absorbent resin are uniformly mixed to form a matrix in a gasket product for a cap fitting, the oxygen absorbent being formed in a different shape from the matrix in the gasket product for a cap, Wherein the foaming agent is foamed to form open pores communicating with the outside in the gasket product for a cap,
Wherein the water absorbent resin is Ethylene Vinyl Alcohol Copolymer (EVOH), and the oxygen absorbent is sodium sulfite or potassium sulfite.

60 to 98% by weight of a base resin made of a thermoplastic resin; 0.1 to 20% by weight of a water absorbent resin; 1 to 20% by weight of an oxygen absorber; And 0.1 to 20% by weight of a porous material,
Wherein the base resin and the water absorbent resin are uniformly mixed to form a matrix in a gasket product for a cap fitting with the same phase and the oxygen absorbent and the porous material are formed into a different phase from the matrix in the gasket product for a cap And are separately dispersed uniformly in the matrix,
Wherein the water absorbent resin is Ethylene Vinyl Alcohol Copolymer (EVOH), and the oxygen absorbent is sodium sulfite or potassium sulfite.

The method according to claim 1,
Wherein the oxygen-absorbing resin composition further comprises 0.1 to 20% by weight of a porous material,
Wherein the porous material is formed in a different form from the matrix in the gasket product for cap fittings and is uniformly dispersed in the matrix separately from the oxygen absorbent.

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4. The method according to any one of claims 1 to 3,
Wherein the particle size of the oxygen absorber is 1 to 900 nm.

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4. The method according to any one of claims 2 and 3,
Wherein the porous material is silica. &Lt; RTI ID = 0.0 > 11. < / RTI >

4. The method according to any one of claims 1 to 3,
Wherein the base resin is composed of a polyolefin resin and a rubber component, and the weight ratio of the polyolefin resin and the rubber component is 2: 1 to 1: 2.

10. The method of claim 9,
Wherein the rubber component is a mixture of an alpha olefin rubber and a styrene butadiene rubber, and the weight ratio of the alpha olefin rubber to the styrene butadiene rubber is from 2: 1 to 1: 2.

A gasket product for a bottle cap manufactured by the oxygen-absorbing resin composition according to any one of claims 1 to 3.

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