JP2000038495A - Composition for cap liner and cap liner therefrom - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a composition for a cap liner, usable as a sealing material of a synthetic resin cap hardly causing abnormal increase of a cap-opening torque, easily opened, and capable of preventing a material from eluting from a liner material when a content obtained by hot filling or by heating and sterilizing after filling, carbonated drinks providing an internal pressure, or a content obtained by aseptic packaging, is packed, and further to obtain the cap liner by using the composition. SOLUTION: This elastomer composition for a cap liner comprises (A) 95-5 wt.% hydrogenated product of a styrene-conjugated diene block copolymer, and/or olefinic copolymer rubber, (B) 5-95 wt.% crystalline polypropylene resin and/or polyethylene resin, and (C) 0.05-10 pts.wt. high degree of polymerization organosiloxane having >=100,000 weight average molecular weight expressed in terms of polystyrene measured by gel permeation chromatography(GPC) based on 100 pts.wt. total of the components A and B.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an elastomer composition for a cap liner used as a sealing material for a synthetic resin cap which is a lid material for a PET container, which is a container for filling soft drinks and the like, and a cap using the same. It is about a liner. More specifically, in the contents of hot beverages such as soft drinks and the contents by heat sterilization after filling, and also in the contents of carbonated beverages and the like under an internal pressure and the contents of aseptic fillings that are frequently seen recently, the hermetically sealed seal is used. A seal made of a synthetic resin cap that is easy to open in actual use, prevents leachable substances from the liner material, and has excellent hygiene, without impairing the performance and without an abnormal increase in opening torque. The present invention relates to an elastomer composition for a cap liner used for a material and a cap liner using the same.

[0002]

2. Description of the Related Art Heretofore, as a method of filling contents such as soft drinks, the method of filling at room temperature with the contents has been proposed.
Hot filling under high temperature of about 0 ° C to 90 ° C,
A method of performing a heat sterilization treatment after room temperature and hot filling was adopted.However, due to recent trends in resource saving and energy saving, and because of excellent flavor retention of the contents after filling, the contents have been Aseptic filling and packaging for filling under aseptic conditions has been promoted. As such a general aseptic filling method, the content liquid to be filled is first sterilized and cooled at a high temperature, and then sterilized with ozone water, hydrogen peroxide and / or peracetic acid separately. Using a packaging container such as a bottle made of polyethylene terephthalate resin (PET) that has been sterilized with water and washed with water, and a container cap with a liner,
The contents are filled at room temperature. When such an aseptic filling method is performed, a major problem of the container cap with the liner is that the opening torque in actual use is abnormally increased as compared with the conventional filling method. Possible causes of such problems include sterilization of the cap container with ozone water, hydrogen peroxide solution, peracetic acid solution, etc. before filling, and lubricant loss on the liner surface due to water washing in the final step, material change, and the like. .

[0003] Further, in order to prevent the increase of the torque, if the lubricant is excessively added, the flavor of the internal solution is affected by the chemical reaction between the lubricant and the sterilizing solution depending on the type and amount of the sterilizing solution and the lubricant. There is a danger that the resulting product will be produced and mixed into the internal solution, or that the lubricant added excessively in the distribution process after filling will bloom on the surface and float on the surface of the internal solution. there were. Japanese Patent Laid-Open No. 2-19116 discloses a container lid for such a sterile filling container.
No. 6 discloses a container lid in which a liner is formed of a composition of a polyolefin containing a higher fatty acid-based lubricant and an ethylene / propylene copolymer rubber. However, in the above-mentioned liner, since a higher fatty acid-based lubricant is added as a lubricant, there is a danger that a substance such as an aldehyde compound which affects the flavor of the contents by reacting with the type of sterilizing solution, particularly ozone, may be generated. There is also a
Since the lubricant has a carbon number of 6 to 30, it has a low molecular weight and, under conditions such as sterilization and water pressure at the time of washing, the opening torque at the time of actual use, which is caused by the loss of the lubricant on the liner surface. An abnormal rise was seen.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to provide a synthetic resin cap liner material which solves the above problems. Specifically, even after performing sterilization treatment of the cap container before filling with ozone water or hydrogen peroxide solution in aseptic filling or peracetic acid, there is no abnormal increase in opening torque at the time of actual use, and There is no product that affects the flavor of the inner solution due to chemical reaction with the sterilizing solution, and there is no danger that the lubricant itself floats on the inner solution surface, and the liner has good moldability. , Hot filling of normal inner solution, heat sterilization treatment, furthermore, even in the inner solution of carbonated beverages, etc., has a good hermetic sealing property without liquid leakage and internal pressure drop,
An object of the present invention is to provide a cap liner composition and a cap liner which are easy to open at the time of actual use and are excellent in hygiene.

[0005]

The present inventors have conducted intensive studies to solve the above problems, and as a result, the following (A) containing a specific amount of a high polymerization degree organopolysiloxane having a specific molecular weight. ), (B), (C) and the liner composed of the component (D) are subjected to a sterilization treatment and a water washing treatment of the cap container before filling with ozone water or hydrogen peroxide water in aseptic filling. After use, there is no abnormal increase in the opening torque during actual use, no products that may affect the flavor of the internal solution due to chemical reaction with the sterilizing solution, and the lubricant itself contains the internal solution. It has been found that it is possible to provide a cap liner that is excellent in hygiene such as no danger of floating on the surface, and has good liner moldability and hermetic sealability, and has completed the present invention. is there.

That is, the elastomer composition for a cap liner of the present invention is characterized by comprising the following components (A), (B) and (C). Component (A): hydrogenated styrene / conjugated diene block copolymer and / or olefin copolymer rubber 95 to 5% by weight Component (B): crystalline polypropylene resin and / or polyethylene resin 5 Component (C): The total amount of component (A) and component (B) having a high polymerization degree of 100,000 or more in terms of polystyrene as determined by gel permeation chromatography (GPC) is 100. 0.05 to 10 parts by weight per part by weight

A cap liner according to another aspect of the present invention is formed by using an elastomer composition for a cap liner comprising the following components (A), (B) and (C). Things. Component (A): hydrogenated styrene / conjugated diene block copolymer and / or olefin copolymer rubber 95 to 5% by weight Component (B): crystalline polypropylene resin and / or polyethylene resin 5 Component (C): The total amount of component (A) and component (B) having a high polymerization degree of 100,000 or more in terms of polystyrene as determined by gel permeation chromatography (GPC) is 100. 0.05 to 10 parts by weight based on parts by weight

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS [I] Elastomer composition for cap liner (1) Constituent components (essential components) (A) Hydrogenated styrene / conjugated diene block copolymer and / or olefin copolymer rubber [ Component (A)] Hydrogenated product of styrene / conjugated diene block copolymer The hydrogenated product of styrene / conjugated diene block copolymer used as component (A) in the elastomer composition for a cap liner of the present invention includes: The conjugated diene is a polymer block composed of butadiene alone or isoprene alone or a mixture of isoprene and butadiene. Specifically, a hydrogenated product of a styrene-butadiene-styrene block copolymer (hereinafter simply referred to as “hydrogenated SB”) -S ”) or hydrogenation of styrene-isoprene-styrene block copolymer. (Hereinafter simply abbreviated as “hydrogenated S-I-I-S”) or a hydrogenated product of styrene / (isoprene / butadiene) / styrene block copolymer (hereinafter simply referred to as “hydrogenated S-I-S”). −
BI-S ". ) And the like. Among these, hydrogenated S-BI-S, which is a mixture of isoprene and butadiene, is preferred as the conjugated diene because it has better slipperiness as a liner, has less sticky feeling, and is superior in preventing torque increase upon opening. In that case, the mixing weight ratio (isoprene / butadiene) is 100 /
It is 0/1/99, preferably 90 / 10-65 / 35.

These hydrogenated styrene / conjugated diene block copolymers have a weight average molecular weight of 50,000 to 50,000.
500,000, preferably 60,000 to 400,0
00, particularly preferably 70,000 to 300,000
And the styrene content is 5 to 50% by weight, preferably 8 to
45% by weight, particularly preferably 10 to 40% by weight,
20-50%, preferably 30-45% when one microstructure is hydrogenated SBS, hydrogenated SIS and hydrogenated SB
In the case of IS, a block copolymer of less than 20%, preferably less than 15%, and having a hydrogenation rate of the conjugated diene block of 80% or more, preferably 95 to 100% is used. Here, "weight average molecular weight" means gel permeation (penetration)
It is a weight average molecular weight in terms of polystyrene measured by chromatography (GPC) under the following conditions. (Conditions) Equipment: 150C ALC / GPC (MILL
Column: AD80M / S (manufactured by Showa Denko KK) 3 solvents: o-dichlorobenzene Temperature: 140 ° C. Flow rate: 1 ml / min Injection volume: 200 ml Concentration: 2 mg / ml (antioxidants 2, 6) 0.2% by weight of 1-t-butyl-p-cresol was added and the concentration was detected by an infrared spectrophotometer MIRAN 1A manufactured by FOXBORO.
Measured at a wavelength of 3.42 μm. If the weight average molecular weight of the hydrogenated styrene / conjugated diene block copolymer exceeds the above range, it is inferior in moldability, and if it is less than the above range, rubber elasticity and mechanical strength are inferior. It is inferior in sex.

Olefin copolymer rubber The olefin copolymer rubber used in the present invention is an elastic body of an amorphous random copolymer containing olefin as a main component, and is measured by an X-ray diffraction method. Low-crystalline or amorphous polymer having a crystallinity of 40% or less.
Among the above-mentioned olefin copolymer rubbers, it is preferable to use a copolymer rubber composed mainly of ethylene and an α-olefin having 3 to 12 carbon atoms. Among them, ethylene-propylene copolymer rubber (EPM), Ethylene / butene-1 copolymer rubber (EBM), ethylene / octene-1
It is more preferable to use a copolymer rubber (EOM), and it is particularly preferable to use an ethylene / octene-1 copolymer rubber (EOM). The ethylene content of these ethylene copolymer rubbers is preferably from 60 to 95% by weight.
In addition, among the olefin copolymer rubbers, it is preferable to use a copolymer rubber containing propylene as a main component, ethylene and an α-olefin having 4 to 12 carbon atoms, and among these, a propylene / ethylene copolymer rubber is preferably used. It is more preferred to use In such a case, the propylene content is preferably 65 to 90% by weight. These olefin copolymer rubbers have a weight average molecular weight of 50,0.
00 to 1,000,000, preferably 60,000 to 8
00,000, particularly preferably 80,000 to 500,
000. If the weight average molecular weight is less than the above range, rubber elasticity and mechanical strength tend to be inferior, and if it exceeds the above range, moldability tends to be inferior. The hydrogenated styrene / conjugated diene block copolymer and / or olefin copolymer rubber used may be used alone or in combination of two or more.

(B) Crystalline polypropylene resin and / or polyethylene resin [Component (B)] In the elastomer composition for a cap liner of the present invention, a crystalline polypropylene resin and / or polyethylene resin is used as the component (B). Crystalline polypropylene resin Examples of the crystalline polypropylene resin include propylene homopolymer, propylene and ethylene and / or C4 to C4.
12. An α-olefin copolymer having a crystallinity of at least 35% by X-ray diffraction, preferably 40% to 8%.
0% is used. The above-mentioned crystalline polypropylene resin has a melt flow rate (MFR, JIS-K675).
8, 230 ° C, 2.16 kg load) 0.01-100
g / 10 minutes, preferably 0.1 to 70 g / 10 minutes, particularly preferably 1 to 50 g / 10 minutes.

Polyethylene Resin The above-mentioned polyethylene resin may be a homopolymer of ethylene and / or a copolymer of ethylene and an α-olefin having 3 to 12 carbon atoms obtained by a known method such as a high-pressure polymerization method or a low-pressure polymerization method. A coalesce having a degree of crystallinity of 30% or more, preferably 35% to 80% by X-ray diffraction is used. The polyethylene resin has a melt flow rate (MFR, JIS-K6760, 190 ° C., 2.16 k
g load) is 0.01 to 100 g / 10 min, preferably 0.1 to 80 g / 10 min, particularly preferably 1 to 50 g / min.
A 10 minute one is used.

(C) High polymerization degree polysiloxane [Component (C)] The high polymerization degree polysiloxane used as the component (C) in the elastomer composition for a cap liner of the present invention includes a methyl group at a side chain and at both ends. In addition to dimethylpolysiloxane (trimethylsiloxy groups at both ends),
Part of the side chain methyl group is hydrogen, phenyl group, vinyl group,
3,3,3-Trifluoropropyl group, those substituted with other alkyl groups, alcohol-modified side chains and / or both terminals, amino-modified, epoxy-modified, polyether-modified,
An organically modified product such as a carboxyl modified product is used, but it is preferable to use a dimethylpolysiloxane in which the side chain and both terminals are methyl groups.

The high polymerization degree organopolysiloxane has a weight average molecular weight of 100,000 or more, preferably 150,000 or more, and particularly preferably 300,000.
0 or more. Here, "weight average molecular weight"
It is a weight average molecular weight in terms of polystyrene measured by gel permeation chromatography (GPC) under the following conditions. (Conditions) Equipment: 150C ALC / GPC (MILL
Column: AD80M / S (manufactured by Showa Denko KK) 3 Solvent: o-dichlorobenzene Temperature: 140 ° C Flow rate: 1 ml / min Injection amount: 200 ml Concentration: 2 mg / ml (antioxidant 0.2% by weight of 2,6-di-t-butyl-p-cresol was added and the concentration was detected by an infrared spectrophotometer MIRAN 1 manufactured by FOXBORO.
Measured by A at a wavelength of 3.42 μm. If the high polymerization degree organopolysiloxane has a weight-average molecular weight of less than the above range, it tends to be inferior to the effect of preventing an increase in opening torque after aseptic filling with sterilization / washing treatment.

(D) Rubber softener and / or liquid paraffin [Component (D)] In the elastomer composition for a cap liner of the present invention, the rubber softener and / or liquid paraffin of the component (D) is used. . Rubber Softener The mineral softener is preferably a mineral oil or synthetic resin. The former mineral oil-based softener is an aromatic ring,
A mixture of a naphthene ring and a paraffin chain in which the number of carbon atoms in the paraffin chain accounts for 50% or more of the total number of carbon atoms is called a paraffinic system, and the number of carbon atoms in the naphthene ring accounts for 30 to 45%. Those are called naphthenics, and those having an aromatic carbon number of more than 30% are called aromatics. Among them, the mineral oil-based softeners suitably used as the component (D) are paraffinic and naphthenic, and have an aromatic hydrocarbon content of 30% or less. Aromatic ones are less preferred in terms of dispersibility for component (A). As the properties of the mineral oil-based softener, the kinematic viscosity at 40 ° C is 20 to 800 cst, preferably 5 to 800 cst.
0-600 cst, pour point between 1450 and 0 ° C, preferably between 130 and 0 ° C, flash point (COC) between 170 and 400
C, preferably 200 to 350C.
Further, as the latter synthetic resin-based softener, polybutene,
Low molecular weight polybutadiene and the like can be used. Liquid paraffin The liquid paraffin belongs to the lubricating oil fraction in terms of boiling point, and is obtained by removing and purifying the unsaturated components and impurities such as aromatics and sulfur contained in the lubricating oil fraction, and having extremely high purity. A mixture of liquid saturated hydrocarbons having a high molecular weight is used.

(2) Additional Components (Optional Components) The polymer composition used in the present invention may contain other additional components as long as the effects of the present invention are not significantly impaired. For example, phenol-based and / or phosphorus-based antioxidants, hindered amine-based light stabilizers, metal soaps, and / or neutralizing agents such as hydrotalcites, and, if necessary, higher fatty acids , Waxes, silicone oil, higher fatty acid amides and other lubricants,
Organic and inorganic pigments such as titanium oxide and phthalocyanine blue, metal deactivators, antistatic agents, fillers, peroxides, nucleating agents, and low-density polyethylene, linear low-density polyethylene, ethylene-vinyl acetate A polymer or the like can be added as long as the effects of the invention are not impaired.

(3) Mixing ratio of composition The mixing ratio in the present invention is determined based on the hydrogenated product of the styrene / conjugated diene block copolymer as the component (A) and / or the olefin copolymer rubber 95 to 5 % By weight, a crystalline polypropylene resin as the component (B), and / or
A high polymerization degree organopolysiloxane having a weight average molecular weight of 100,000 or more in terms of polystyrene by gel permeation chromatography (GPC), which is the component (C), based on 100 parts by weight of the total amount of 5 to 95% by weight of the polyethylene resin. Or a composition containing 0.05 to 10 parts by weight or a total of 100 parts by weight of the component (A) and the component (B), and a rubber softener and / or a liquid paraffin component (D) of 0 to 10 parts by weight.
100 parts by weight, and 0.05 to 10 parts by weight of the high polymerization degree organopolysiloxane of the component (C) based on 100 parts by weight of the total of the components (A), (B) and (D). A composition.

The total of the above components (A) and (B) is 100
The amount of the hydrogenated product of the styrene / conjugated diene block copolymer as the component (A) and / or the amount of the olefin copolymer rubber is 95 to 5% by weight, preferably 90 to 10% by weight. % By weight, particularly preferably 80 to 20
% By weight. When the amount is less than 5% by weight, the sealing performance is deteriorated. When the amount exceeds 95% by weight, the moldability is deteriorated. The high polymerization degree organopolysiloxane as the component (C) is 0.05 to 10 parts by weight, preferably 0.1 to 5 parts by weight based on 100 parts by weight of the total of the components (A) and (B).
Parts by weight, particularly preferably 0.5 to 3 parts by weight. If the compounding amount of the high polymerization degree organopolysiloxane is less than the above range, there is no effect of preventing the torque from increasing, and if the compounding amount exceeds the above range, the moldability deteriorates. Further, the softening agent for rubber and / or the liquid paraffin component (D) is from 1 to 100 parts by weight, preferably from 10 to 80 parts by weight, particularly preferably from 100 parts by weight in total of the components (A) and (B). Is 30 to 70 parts by weight. When the component (D) exceeds 100 parts by weight, the wax float tends to be deteriorated. When a hydrogenated styrene / conjugated diene block copolymer is used as the component (A), the component (D) is preferably used. When an olefin copolymer rubber is used as the component (A), stickiness may appear on a molded product when a large amount of the component (D) is added.

(4) Preparation and Production Method of Composition The preparation of the elastomer composition for a cap liner of the present invention is carried out by a known method using components (A), (B), (C) and (D), For example, Henschel mixer, V
After mechanically mixing with a blender, tumbler blender or the like, it can be produced by known mechanical melting and kneading. Specifically, general melt kneaders such as a Hanbury mixer, various kneaders, a single screw extruder, a twin screw extruder, and a twin screw kneader can be used. It is also possible to use those obtained by melt-kneading the organopolysiloxane with a high degree of polymerization and polyethylene or polypropylene in advance using a twin-screw kneading extruder, a Hanbury mixer, various types of kneaders, etc., and pelletizing.

(6) Molding of cap liner The elastomer composition for a cap liner of the present invention is tightly molded in a cap shell using a known liner molding method. As a liner molding method, for example, 0.5 to 1.0 m
After molding into a sheet with a thickness of m, insert it into a punched cap with a diameter that matches the shape of the cap, and bond it, or
An in-shell molding method and a general insert injection molding method in which a fixed amount of molten resin extruded by an extruder is dropped inside a cap and embossed under cooling to form a liner shape, and the like. Note that the in-shell molding method is an excellent molding method in terms of mass productivity.

[0021]

The present invention will be described more specifically with reference to the following examples and comparative examples. Where the raw materials used,
The evaluation method is as described below. [I] Raw materials used Component (A): hydrogenated styrene / conjugated diene block copolymer and / or olefin copolymer rubber

[0022]

[Table 1]

A-4: An ethylene content of 78% by weight and a melt flow rate (230 ° C., 2.16 kg) of 3.6
g / 10 min. amorphous ethylene / propylene copolymer rubber (EPM) A-5: ethylene content 85% by weight, melt flow rate (230 ° C., 2.16 kg) 6.7 g / 10 min. Butene-1 copolymer rubber (EBM) A-6: Ethylene octene-1 copolymer rubber (EOM) having an ethylene content of 76% by weight and a melt flow rate (230 ° C., 2.16 kg) of 11 g / 10 min.

Component (B): polypropylene resin B-1: Novatec PP MA03 manufactured by Nippon Polychem Co., Ltd. Melt flow rate (230 ° C., 2.16 kg) 25 g / 10 min: high-density polyethylene resin B-2: Nippon Polychem ( Novatec HD HJ490 Melt Flow Rate (190 ° C., 2.16 kg) 20 g / 10 min: Linear low-density polyethylene resin B-3: Novatec LL UF240 Melt Flow Rate (190 ° C., 2.16 kg) manufactured by Nippon Polychem Co., Ltd. 16 kg) 2.1 g / 10 min: Low density polyethylene resin B-4: Novatec LD LF420M manufactured by Nippon Polychem Co., Ltd. (190 ° C., 2.16 kg) 2.2 g / 10 min

Component (C): high degree of polymerization dimethylpolysiloxane

[0026]

[Table 2]

Component (D): Softener for rubber and / or liquid paraffin D-1: PW90 manufactured by Idemitsu Kosan Co., Ltd. [Kinematic viscosity (40
° C) 95.5 cst, pour point-15.0 ° C flash point (CO
C) 272 ° C] D-2: CP68N manufactured by Idemitsu Kosan Co., Ltd. [Kinematic viscosity (4
0 ° C) 68.1 cst, pour point-12.5 ° C flash point (C
OC) 238 ° C]

Lubricant component: Lubricant 11: Neutron Ole manufactured by Nippon Seika Co., Ltd.
Amide Lubricant 1-2: Neutron-SE manufactured by Nippon Seika Co., Ltd.
rucamide

[II] Evaluation method For the measurement samples of the following evaluations, an injection pressure of 500 kg / cm ² and an in-line screw type injection molding machine (a small injection molding machine manufactured by Toshiba Machine Co., Ltd .: IS90B) were used.
120 molded at an injection temperature of 220 ° C and a mold temperature of 40 ° C
A mm × 80 mm × 2 mmt sheet was used. For the following evaluation ~ by the in-shell mold method described above,
Using a cap made of polypropylene with a liner obtained by molding into a liner, a container with a lid under the above filling conditions was used. JIS-A hardness Based on JIS-K-6301. Liner moldability Each composition is heated to 210 ° C., fed into the cap shell in a molten state, pressed by the in-shell mold method, and formed into a liner in the cap. 1 obtained
The 00 cap liners were visually inspected and rated according to the following criteria. ：: No liner molding failure ×: Liner chipping, burr or other molding failure of 1% or more

[0030] Hermetically-sealing properties: For 10 containers obtained under the above-mentioned filling conditions, 50c
From the height of m, it was inverted and dropped on an iron plate having a tilt angle of 10 degrees, and the leakage from the cap seal portion was evaluated according to the following criteria. ：: No leakage at all ×: Even one leak was observed Openability The sample container after tightening the cap under the above-mentioned filling conditions was stored in a 60 ° C constant temperature bath and a 5 ° C refrigerator for one week. Thereafter, the opening torque value was measured, and the measured torque value was evaluated according to the following criteria. (10 tests) ：: All of them show appropriate torque value (10 to 20 kg · cm) △: Intermediate torque value (5 to 10 kg · cm or 20 to 2)
5 kg.cm or more). ×: inappropriate torque value (less than 5 kg · cm or 25 kg
・ Cm or more). Flavor Retention Under the above-mentioned filling conditions, the sample container after tightening the cap is stored in a 60 ° C constant temperature bath and in a 5 ° C refrigerator in a lying state for one week, then opened and the flavor of the content liquid is subjected to a sensory test. Evaluation was made according to the following criteria. (Test number: 10) ○: All samples showed the same flavor as the initial stage ×: At least one that had a slightly different flavor from the initial stage

[III] Examples and Comparative Examples Examples 1 to 17 and Comparative Examples 1 to 10 (1) Production of Composition In addition to the formulations shown in Tables 3 and 4, this formulation 100
0.1 part by weight of a phthalocyanine-based blue face was added to 100 parts by weight, and mixed with a Henschel mixer. L / D: 3
3. The mixture was melt-kneaded at a set temperature of 200 ° C. with a twin-screw extruder having a cylinder diameter of 45 mm to obtain pellets of the liner composition. At the time of compounding, a masterbatch kneaded with polyethylene at a ratio of 1: 1 was used for the organopolysiloxane having a high degree of polymerization. (2) Liner Molding The obtained composition was molded at 210 ° C. by an in-shell mold method in a polypropylene cap shell having a nominal diameter of 28 mmφ.

(3) Filling condition The cap with the liner obtained by the in-shell mold molding was sterilized in advance using ozone water under the following conditions, and immediately placed in a PET bottle with a capacity of 1.5 liters. The container was filled at room temperature, and was wound with a tightening torque of 11.0 kg · cm using a Magna torque head of a capping machine manufactured by Alcoa to obtain a sealed container containing a mineral water. (10 tests) Cap sterilization treatment with ozone water After prewashing with hot water (water pressure 0.8 kg / cm ² ) at 80 ° C. for 20 seconds, immersion in 30 ppm high concentration ozone water for 80 seconds, high concentration ozone After washing with a jet shower of water (water pressure 1.0 kg / cm ² ) and a jet shower of low-concentration ozone water of 1 ppm or less (water pressure 0.6 kg / cm ² ) for several seconds, draining was performed with aseptic air. (4) Evaluation The evaluation of the components blended at the respective blending ratios shown in Tables 3 and 4 was evaluated according to the above-described evaluation method, and the results were shown in Tables 3 and 4.
Shown in

[0033]

[Table 3]

[0034]

[Table 4]

[0035]

The composition for a cap liner of the present invention and the cap liner comprising the same have good liner moldability by the in-shell mold method, and are filled with ozone water or hydrogen peroxide solution before aseptic filling. Even after the cap container has been sufficiently sterilized, there is no abnormal increase in the opening torque at the time of actual use opening, the opening at the time of actual use is easy, and the flavor retention of the content liquid is excellent. It is suitably used as a cap liner material excellent in hygiene that does not float on the solution surface. Furthermore, there is no liquid leakage even after hot filling of the inner solution such as a soft drink and heat sterilization treatment, and also has a good hermetic sealing property without lowering the inner pressure even in the inner solution of the carbonated beverage and the like, It is easy to open in actual use, and is suitably used as a cap liner material excellent in hygiene.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI theme coat ゛ (reference) (C08L 53/02 83:04) F term (reference) 3E084 AA12 AA24 AB01 FB01 GA01 GB01 HA02 HB03 HC06 4J002 AC034 AE035 AE054 BA014 BB03X BB05W BB05X BB12X BB14W BB14X BB15W BB15X BB174 BP01W CP033 CP035 CP053 CP083 CP093 CP143 CP183 EF056 EP016 FD040 FD070 FD090 FD175 FD176 GG01

Claims (5)

[Claims] 1. An elastomer composition for a cap liner, comprising the following components (A), (B) and (C). Component (A): hydrogenated styrene / conjugated diene block copolymer and / or olefin copolymer rubber 95 to 5% by weight Component (B): crystalline polypropylene resin and / or polyethylene resin 5 Component (C): The total amount of component (A) and component (B) having a high polymerization degree of 100,000 or more in terms of polystyrene as determined by gel permeation chromatography (GPC) is 100. 0.05 to 10 parts by weight based on parts by weight 2. The elastomer composition for a cap liner according to claim 1, wherein the component (C) of the high polymerization degree organopolysiloxane is compounded in the following ratio, and the following component (D) is compounded. Component (C): Highly polymerized organopolysiloxane 0.05 to 10 parts by weight based on 100 parts by weight of the total of component (A), component (B) and component (D) Component (D): a softener for rubber and And / or liquid paraffin 1 to 100 parts by weight based on 100 parts by weight of the total of component (A) and component (B) 3. The elastomer composition for a cap liner according to claim 1, wherein the lubricant of the component (E) is blended in the following ratio. Component (E): Lubricant With respect to 100 parts by weight of component (A), component (B) and component (C), or component (A), component (B), component (C) and component (D) in total. 0.05-1.0 parts by weight 4. A cap liner formed using an elastomer composition for a cap liner comprising the following components (A), (B) and (C). Component (A): hydrogenated styrene / conjugated diene block copolymer and / or olefin copolymer rubber 95 to 5% by weight Component (B): crystalline polypropylene resin and / or polyethylene resin 5 Component (C): The total amount of component (A) and component (B) having a high polymerization degree of 100,000 or more in terms of polystyrene as determined by gel permeation chromatography (GPC) is 100. 0.05 to 10 parts by weight based on parts by weight 5. The cap liner according to claim 4, wherein the elastomer composition for a cap liner is the elastomer composition for a cap liner according to any one of claims 2 to 3.