JPH11165751A - Pull-open cap - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pull-open cap or an integrated cap of pull-open cap and a hinge cap which has the pull-open property, is not deformed even when heated for 30-45 minutes at 100-130 deg.C, is not degraded in the weld strength of a pull-ring part, and is 60 deg.C or over in heat distortion temperature. SOLUTION: A pull-open cap or an integrated cap of the pull-open cap with a hinge cap is obtained by injection-molding the resin composition where 35-60 pts.wt. hydrogenated styrene-butadiene rubber of 3-6 g/10 min. in melt flow rate (230 deg.C, 21.18 N) is blended to 100 pts.wt. of propylene-ethylene block copolymer resin with not less than 20 wt.% in xylene extraction at 25 deg.C of 3-100 g/10 min. in melt flow rate (230 deg.C, 21.18 N).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polyolefin resin pull-open cap and a pull-open cap-hinge cap having a pull-open property (easy pull-out property). More specifically, it is obtained by molding a resin composition obtained by blending a specific polypropylene block copolymer resin and a specific elastomer, or a specific polypropylene block copolymer resin and a specific elastomer and a linear low-density polyethylene resin. Pull-open cap or pull-open cap-hinge cap, 100-130 ° C
It is not deformed even if heat treatment is performed, and it is also a pull ring (a ring to put a finger on when tearing the pull open cap)
The present invention relates to a pull-open cap having a pull-open property and a pull-open cap-hinge cap that does not lower the weld strength of the present invention.

[0002]

2. Description of the Related Art It is well known that a high-pressure low-density polyethylene resin or a linear low-density polyethylene resin is used as a polyolefin resin pull-open cap resin for medical and food use. JP-A-2-45362 discloses a hinged pull-open cap using a resin obtained by blending a linear low-density polyethylene resin with a polypropylene resin.
No. 6 discloses polypropylene, specific ethylene α-
There has been reported a polypropylene composition comprising an olefin copolymer and a specific block copolymer, which is easily heat-fused and easily shredded.

However, known high-pressure low-density polyethylene resins, linear low-density polyethylene resins,
JP-A-45362 discloses a hinged pull-open cap in which a polypropylene resin is blended with a linear low-density polyethylene resin, or the polypropylene disclosed in JP-B-5-6576, a specific ethylene / α-olefin copolymer and a specific ethylene-α-olefin copolymer. The heat-fusing property of the block copolymer and the easy-to-shear polypropylene composition,
The molded articles selected using this composition have good pull-opening properties and good pull ring weld strength,
When heat treatment is performed at 0 ° C., the pull-open cap molded using the high-pressure low-density polyethylene resin and the linear low-density polyethylene resin is deformed, and the linear low-density polyethylene resin disclosed in JP-A-2-45362 is deformed. A pull-open cap formed by using a composition obtained by blending a polypropylene resin with a high-density polyethylene resin is deformed by heat treatment at 100 to 130 ° C. when the mixing ratio of the linear low-density polyethylene resin is increased, and the pull ring welds. Part strength is reduced, the molded product obtained by using the composition disclosed in JP-B-5-6576, a composition comprising a specific ethylene / α-olefin copolymer and a specific block copolymer has a weld strength of Although it is kept, there is a drawback that the heat deformation temperature is lower than 60 ° C. and the film is deformed by heat treatment.

[0004]

SUMMARY OF THE INVENTION The present inventors have a pull-open property, and carry out a heat treatment at 100 to 130 ° C. for 30 to 4 hours.
The inventors conducted extensive research on a pull-open cap having a heat deformation temperature of 60 ° C. or more, which did not deform even after 5 minutes and did not reduce the weld strength of the pull ring portion. As a result, a specific elastomer for a specific polypropylene block copolymer resin,
Alternatively, by using a composition in which a specific elastomer and a linear low-density polyethylene resin are blended with a specific polypropylene block copolymer resin, a pull-open cap or a pull-open resin using the obtained resin composition is obtained.
The heat-deformation temperature of 60 ° C. or higher, which has a pull-open property, does not deform even when heat-treated at 100 to 130 ° C. for 30 to 45 minutes, and does not reduce the weld strength of the pull ring portion. The inventors have found that the cap becomes an integral cap of a pull-open cap and a pull-open cap-hinge cap, and based on this finding, completed the present invention. As is apparent from the above description, an object of the present invention is to have a pull-open property,
Not deformed by heat treatment for 30 to 45 minutes at which the weld strength of the pull ring portion is not reduced. A pull-open cap or a pull-open cap having a heat deformation temperature of 60 ° C. or more.
For the purpose of providing an integral cap of a hinge cap, medical oil such as a drip container which performs heat treatment for disinfection and sterilization, cooking oil, edible oil such as salad oil and sesame oil,
An object of the present invention is to provide a pull-open cap or a pull-open cap-hinge cap having a pull-open property for foods such as soy sauce, sauce, vinegar, mirin, ponds, various dressings, and fruit drinks.

[0005]

(1) A propylene-ethylene block copolymer resin having a melt flow rate (230 ° C. 21.18N) of 3 to 100 g / 10 minutes and an xylene extraction amount at 25 ° C. of 20% by weight or more. The melt flow rate (230 ° C. 21.1
8N) A pull-open cap or a pull-off cap formed by molding a resin composition containing 35 to 60 parts by weight of hydrogenated styrene / butadiene rubber in 3 to 6 g / 10 minutes.
Puncap-An integrated cap with a hinge cap. (2) 35 to 60 hydrogenated styrene-butadiene rubber having a melt flow rate (230 ° C. 21.18 N) of 3 to 6 g / 10 min based on 100 parts by weight of the propylene-ethylene block copolymer resin according to claim 1. Parts by weight, melt flow rate (190 ° C. 21.18N) 5 to 50 g /
A pull-open cap or pull-open formed by molding a resin composition containing 5 to 25 parts by weight of a linear low density polyethylene resin having a density of 0.910 to 0.930 g / cm ² for 10 minutes. Cap-Integrated cap of hinge cap. (3) A propylene-ethylene block copolymer resin having an xylene extraction amount at 25 ° C. of 20% by weight or more
The hydrogenated styrene / butadiene rubber according to the above item 1 is added to 100 parts by weight of a mixture consisting of 0% by weight and a total of 100% by weight of 50 to 30% by weight of the other propylene-ethylene block copolymer resin. A resin prepared by mixing 35 to 60 parts by weight of a hydrogenated styrene / butadiene rubber as described in the above item 2 and 5 to 25 parts by weight of a linear low-density polyethylene resin. An integrated cap of a pull-open cap or a pull-open cap-hinge cap formed by molding the composition.

(4) With respect to 100 parts by weight of the resin composition according to any one of the above items (1) and (2),
1,3-bis (t-butylperoxyisopropyl) benzene, 2,5-di-methyl-2,5-di (t-butylperoxy) hexane or one or more of these are added to 0.1%.
An integrated cap of a pull-open cap or a pull-open cap-hinge cap formed by molding a resin composition blended in a ratio of 001 to 0.1 parts by weight. (5) The fatty acid ester, the aliphatic alcohol, the fatty acid dialkanolamide, the fatty dialkanolamine, and the higher alcohol are further used as lubricants with respect to 100 parts by weight of the resin composition according to any one of the above items 1 and 2. An integrated cap of a pull-open cap or a pull-open cap-hinge cap formed by molding a resin composition containing 0.1 to 1 part by weight of a fatty acid amide or one or more of these. (6) A pull-open cap or a pull-open cap obtained by heat-treating the integrated cap of the pull-open cap or the pull-open cap-hinge cap according to any one of the above items 1 to 5 at 100 to 130 ° C. -Pun cap-Integral cap of hinge cap.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The propylene-ethylene block copolymer resin used in the present invention has a melt flow rate (230 ° C. 21.18 N) of 3-1 from the viewpoint of pull-open property.
A propylene-ethylene block copolymer resin of 00 g / 10 min, preferably 10-70 g / 10 min, defined in FDA section 177.1520 as a propylene-ethylene block copolymer based on polypropylene. 20% by weight xylene solubles at 25 ° C
The above block copolymer, and the propylene-
1,3-bis (t-butylperoxyisopropyl) benzene (POX1), 2,3-bis (t-butylperoxyisopropyl) benzene
5-di-methyl-2,5-di (t-butylperoxy)
Hexane (POX2) or a mixture of one or more of these in a specific amount may be used. Hydrogenated styrene / butadiene rubber has a melt flow rate (230 ° C., 21.1.
8N) 3-6 g / 10 min hydrogenated styrene-butadiene rubber. The linear low-density polyethylene resin used in the present invention has a melt flow rate (190 ° C. 21.1).
8N) 5-50 g / 10 min, preferably 10-40 g /
The density is 0.910 to 0.930 g / cm ³ for 10 minutes.

The lubricant used in the present invention includes glycerin monopalmitate, glycerin monostearate, glycerin monooleate, glycerin monolaurate, butyl laurate, butyl stearate, decyl laurate, decyl stearate, lauryl stearate, Fatty acid esters such as stearyl stearate, decyl alcohol, lauryl alcohol, myristyl alcohol, cetyl alcohol, aliphatic alcohols such as stearyl alcohol, behenic acid diethanolamide, oleic acid diethanolamide, stearic acid diethanolamide, myristic acid diethanolamide, Fatty acid dialkanolamides such as lauric acid diethanolamide, capric acid diethanolamide, caprylic acid diethanolamide; Aliphatic dialkanolamines such as rudiethanolamine, oleyldiethanolamine, stearyldiethanolamine, myristyldiethanolamine, lauryldiethanolamine, decyldiethanolamine, octyldiethanolamine, and hexyldiethanolamine; higher fatty acid amides such as oleic amide and erucic acid amide; .

These lubricants enhance the releasing effect of the cap and the pull ring (pull-out grip portion) from the mold when forming a pull-open cap or an integrated cap of a pull-open cap and a hinge cap. There is also an antistatic effect depending on the type added as a static effect.
The blending ratio of the lubricant is 0.1 parts with respect to 100 parts by weight of a resin composition obtained by mixing a propylene-ethylene block copolymer resin with a specific elastomer or a specific amount of a linear low density polyethylene resin further. ~ 1.
0 parts by weight, preferably 0.3 to 0.6 parts by weight, and one or more of these may be used in combination.

The resin composition used for molding the integrated cap of the pull-open cap or the pull-open cap-hinge cap according to the present invention has a weight within a range not impairing the effects of the present invention, that is, 50 parts by weight based on the composition. %, Preferably 30% by weight or less, low-density polyethylene, polyvinyl acetate, ethylene-vinyl acetate copolymer and partially saponified products thereof, inorganic fillers (talc, mica, glass fiber, wollastonite, zeolite, calcium carbonate) , Magnesium hydroxide, etc.), light stabilizers, phosphorus antioxidants such as diarylpentaerythritol phosphite, tetrakis [methylene-3- (3 ′, 5′-di-t)
-Butyl-4'-hydroxyphenyl) propionate] a phenolic antioxidant such as methane, a neutralizing agent such as higher fatty acid calcium, an antiblocking agent,
1,3,2,4-dibenzylidene sorbitol, 1,
3,2,4-di (paramethylbenzylidene) sorbitol, 1,3,2,4-di (paraethylbenzylidene) sorbitol, 1,3,2,4-di (2,4-dimethylbenzylidene) sorbitol and the like Clarifying agent, aluminum bis (pt-butylbenzoate) hydroxy, sodium-bis (pt-butylphenyl) phosphate, sodium-2,2'-methylene-bis (4,6-di-t- Nucleating agents such as butylphenyl) phosphate,
A radical generator and various coupling agents (silane-based, titanate-based, boron-based, aluminate-based) can be added.

The resin composition for molding the pull-open cap or the pull-open cap-hinge cap according to the present invention comprises a melt flow rate (2).
30 ° C. 21.18 N) is a specific propylene-ethylene block copolymer resin having a melt flow rate (230 ° C. 21.18 N) of 3 to 6 g for 3 to 100 g / 10 min.
/ 10 min of hydrogenated styrene-butadiene rubber or melt flow rate (230 ° C. 21.1
8N) is added to a specific polypropylene block copolymer resin having a melt flow rate (230
Hydrogenated styrene-butadiene rubber and a melt flow rate (190 ° C. 21.18 N) of 3 to 6 g / 10 min.
21.18N) is a resin composition containing a specific amount of a linear low-density polyethylene resin of 5 to 50 g / 10 minutes, or
A predetermined amount of the lubricant and, if necessary, various additives are mixed with the composition using a usual mixing device, for example, a Henschel mixer (trade name), a super mixer, a ribbon blender, a tumbler mixer, a Banbury mixer, and the like, With a single-screw or twin-screw extruder or roll, the melt-kneading temperature is 150 to 300 ° C, preferably 180 to 250 ° C.
It can be obtained by melt-kneading pelletizing at ° C.

[0012]

EXAMPLES The present invention will now be described specifically with reference to examples and comparative examples, but the present invention is not limited to these examples. The evaluation method used in the examples and comparative examples was based on the following method. 1) Melt flow rate of propylene-ethylene block copolymer resin (230 ° C. 21.18 N): JIS
Complies with K6758. 2) Melt flow rate of linear low-density polyethylene resin (190 ° C. 21.18 N): based on JIS K6760. 3) Xylene extraction: 2.54 cm long, 2.54 c wide
5 g of a sample having a thickness of 0.1 mm and a thickness of 0.1 mm is dissolved in 1 liter of a xylene solution while refluxing at 25 ° C. for 1 hour, and the amount of extraction is measured. 4) Pull-open property: Using a single-axis granulator, using pellets granulated at a melt-kneading temperature of 220 ° C., and using an injection molding machine, a round pull-open cap (diameter 30 mm, height 18)
mm, wall thickness 1.2 mm, tearing wall thickness 0.2 mm, pull ring outer diameter 17 mm, wall thickness 1.0 mm), and stand in a constant temperature room at a temperature of 23 ± 2 ° C and a humidity of 50 ± 5% for 48 hours. After that, measure the tear strength using a tensile tester,
When the value was less than 4 kg, it was judged as good, and when it was 4 kg or more, it was judged as bad.

5) Weld strength: using a single-axis granulator, using pellets granulated at a melt-kneading temperature of 220 ° C., and using a injection molding machine, a round pull-open cap (diameter: 30 m)
m, height 18mm, wall thickness 1.2mm, tear part wall thickness 0.2mm, pull ring outer diameter 17mm, wall thickness 1.0m
m) was molded, left in a constant temperature room at a temperature of 23 ± 2 ° C. and a humidity of 50 ± 5% for 48 hours, and then heated for 30 minutes with a heat sterilization tester (TOMY, model SR-240) set at 121 ° C. Perform processing. After treatment, temperature 23 ± 2 ℃, humidity 50 ± 5%
After standing in a constant temperature chamber for 24 hours, the welded portion of the pull ring was bent to determine whether the weld was broken or notched. 6) Deformation: A round pull-open cap (diameter: 30 mm, height: 18 mm, wall thickness: 1.2 mm) using a single-axis granulator, using pellets granulated at a melt-kneading temperature of 220 ° C., and using an injection molding machine. , Tearing part thickness 0.2mm, pull ring outer diameter 17mm, wall thickness 1.0mm), temperature 23 ± 2
12 hours after standing in a constant temperature room at 50 ° C and 50 ± 5% for 48 hours.
Heat sterilization tester set to 1 ° C (TOMY, Model S
(R-240) for 30 minutes. If the cap body or pull ring is deformed after processing,
Those without deformation were judged to be good.

7) Mold releasability: using a uniaxial granulator, using pellets granulated at a melt-kneading temperature of 220 ° C., and using a injection molding machine, a circular pull-open cap (diameter 30 mm,
Height 18mm, wall thickness 1.2mm, tearing wall thickness 0.2
mm, pull ring outer diameter 17 mm, wall thickness 1.0 mm). If the pull ring remains on the fixed side of the mold, or if the pull-open cap is pulled by the fixed side and even a part of the pull-open cap is torn, it is defective. And no mold release from the mold was judged to be good. 8) Hinge strength: A three-point hinge cap having a hinge thickness of 0.2 mm is formed, the cap is fixed to a torque meter, the lid is set upright, and then turned to the right to measure the hinge strength of the hinge. Good if the measured value is 2.0 kgf-cm or more,
Less than 2.0 kgf-cm was determined to be defective. 9) Thermal deformation temperature: Based on JIS K7207 Hard Plastic Deflection Temperature Test Method B Method. Measurement temperature is 60
C. or more was judged as good, and less than 60 ° C. was judged as bad.

Examples 1 to 23 As Examples 1 to 23, the melt flow rate (230
Propylene-ethylene block copolymer pellets (PP) having a xylene extraction amount of 25% by weight and a density of 0.901 g / cm ³ at 50 ° C., 21.18 N) 50 g / 10 min, 25 ° C.
Resin 1), melt flow rate (190 ° C. 21.18)
N) 3.5 g / 10 min, hydrogenated styrene-butadiene rubber (elastomer A) having a density of 0.890 g / cm ³ , and a melt flow rate (190 ° C. 21.18 N) 20 g /
Linear low-density polyethylene resin (PE resin 1) having a density of 0.920 g / cm ³ for 10 minutes, glycerin monosaterate (lubricant A), stearyl alcohol (lubricant B), and diethanol laurate as lubricants -Luamide (lubricant C), stearyldiethanolamine (lubricant D), oleic amide (lubricant E), tris (2,4-di-t-butylphenyl) phosphite (phosphoric acid prevention) as an antioxidant, Tetrakis [methylene-3- (3 ′,
5'-di-t-butyl-4'-hydroxyphenyl) propionate] methane (anti-ferric acid), and calcium stearate as a neutralizing agent in a mixing ratio shown in Tables 1 and 2 below, respectively, in a tumbler mixer, After mixing for 10 minutes, the mixture was extruded and pelletized at a melt-kneading temperature of 220 ° C. using a single-screw extruder having a diameter of 45 mm. Using the pellets obtained in Examples 1 to 23, an integral cap of a pull-open cap and a pull-open cap-hinge cap is formed, and pull-opening property, weld strength, deformation, mold release property, hinge cap are formed. Evaluation of the twist strength and heat deformation temperature was performed. The results are shown in Tables 1, 2 and 3 below.

Examples 24-27 As Examples 24-27, the melt flow rate (230
C. 21.18N) 50 g / 10 min, 25 ° C. xylene extraction amount 25%, propylene having a density of 0.901 g / cm ³ .
Ethylene block copolymer pellets (PP resin 1), melt flow rate (230 ° C 21.18N) 3g / 1
0 min, propylene-ethylene block copolymer pellets (PP resin 2) having a xylene extraction amount of 25% by weight at 25 ° C. and a density of 0.901 g / cm ³ , a melt flow rate (230 ° C. 21.18N) 100 g / 10 minutes, 25 ° C
A propylene-ethylene block copolymer pellet (PP resin 3) having a xylene extraction amount of 25% and a density of 0.901 g / cm ³ , a melt flow rate (190 ° C. 21.18)
N) 3.5 g / 10 min, hydrogenated styrene-butadiene rubber (elastomer A) having a density of 0.890 g / cm ³ , and a melt flow rate (190 ° C. 21.18 N) 20 g /
10 minutes, linear low-density polyethylene resin (PE resin 1) having a density of 0.920 g / cm ³ , melt flow rate (1
90 ° C. 21.18 N) 5 g / 10 min, density 0.920
g / cm ³ linear low density polyethylene resin (PE resin 2), melt flow rate (190 ° C, 21.18N)
50 g / 10 min, linear low-density polyethylene resin (PE resin 3) having a density of 0.920 g / cm ³ , lubricant A as a lubricant, tris (2,4-di-t-butylphenyl) phosphite as an antioxidant (Phosphoric acid prevention), tetrakis [methylene-3- (3 ′, 5′-di-t-butyl-4 ′)
-Hydroxyphenyl) propionate] methane (prevented from ferric acid) and calcium stearate as a neutralizing agent were placed in a tumbler mixer at the blending formulation and blending ratio shown in Table 3 below, and mixed for 10 minutes. Melt kneading temperature 2
Extruded and pelletized at 20 ° C. Each of the pellets obtained in Examples 24 to 27 was used to form a pull-open cap and a pull-open cap-hinge cap, and the pull-open property, weld strength,
The deformation, mold releasability, hinge cap strength, and heat deformation temperature were evaluated. The results are shown in Table 3 below.

Comparative Examples 1 to 8 As Comparative Examples 1 to 8, each of the components was placed in a tumbler mixer at the compounding ratio and mixing ratio shown in Table 4 below.
After mixing for 1 minute, the mixture was melt-kneaded and pelletized according to Examples 1 to 23. Using the pellets obtained in Comparative Examples 1 to 8, an integral cap of a pull-open cap and a pull-open cap-hinge cap was formed, and the pull-open property, weld strength, deformation, mold release property, and hinge cap were formed. Evaluation of the twist strength and heat deformation temperature was performed. The results are shown in Table 4 below.

Comparative Examples 9 to 17 As Comparative Examples 9 to 17, the melt flow rate (230 ° C.)
21.18N) Propylene-ethylene block copolymer pellets (PP resin 1) having 50 g / 10 min, xylene extraction amount at 25 ° C. of 25% by weight, density of 0.901 g / cm ³ , melt flow rate (230 ° C. 21.18)
N) 50 g / 10 min propylene homopolymer pellets (PP resin 4), melt flow rate (230 ° C. 2
1.18N) 10 g / 10 min, density 0.900 g / cm
³ , propylene-ethylene random copolymer pellets with 2.5% by weight of ethylene (PP resin 5), melt flow rate (230 ° C. 21.18N) 10 g / 10 minutes, density 0.900 g / cm ³ , ethylene amount 4 Propylene-ethylene-butene random copolymer pellets (PP resin 6) having a weight ratio of 0.5% by weight and a butene amount of 2.7% by weight, a melt flow rate (230 ° C. 21.18N) 50 g / 10 minutes,
Xylene extraction amount at 25 ° C. 6% by weight, density 0.90
1 g / cm ³ propylene-ethylene block copolymer pellets (PP resin 7), melt flow rate (190
C 21.18N) 3.5 g / 10 min, density 0.890
g / cm ³ hydrogenated styrene-butadiene rubber (elastomer A), melt flow rate (190 ° C. 21.1)
8N) 20 g / 10 min, linear low-density polyethylene resin (PE resin 1) having a density of 0.920 g / cm ³ , lubricant A as a lubricant, and tris (2,4-di-t-
Butylphenyl) phosphite (phosphoric acid resistant), tetrakis [methylene-3- (3 ′, 5′-di-t-butyl-
[4'-Hydroxyphenyl) propionate] methane (anti-ferric acid) and calcium stearate as a neutralizing agent were respectively added to a tumbler mixer in the mixing formula and mixing ratio shown in Table 5 below, and mixed for 10 minutes.
The mixture was melt-kneaded and pelletized according to ２３23. Using the pellets obtained in Comparative Examples 9 to 17, an integral cap of a pull-open cap and a pull-open cap-hinge cap was formed, and pull-opening property, weld strength, deformation, mold release property, and hinge cap were formed. Evaluation of the twisting strength and heat deformation temperature was performed. The results are shown in Table 5 collectively.

Comparative Examples 18 to 25 As Comparative Examples 18 to 25, the melt flow rate (230
Propylene-ethylene block copolymer pellets (PP) having a density of 0.901 g / cm ^{3 and} a xylene extraction amount of 25% by weight at 25 ° C.
Resin 1), melt flow rate (230 ° C. 21.18)
N) 50 g / 10 min, xylene extraction amount at 25 ° C. 6
Propylene-ethylene block copolymer pellets (PP resin 7) having a weight percentage of 0.901 g / cm ³ and a melt flow rate (230 ° C. 21.18 N) of 45 g / 10
Propylene-ethylene block copolymer pellets (PP resin 8) having a xylene extraction amount of 16% by weight at 25 ° C. and a density of 0.901 g / cm ³ , and a melt flow rate (190 ° C. 21.18N) 3.5 g / 10 minutes Styrene-butadiene rubber (elastomer A) having a density of 0.890 g / cm ³ and a melt flow rate (190 ° C.)
21.18N) 3.5 g / 10 min, density 0.890 g
/ Cm ³ ethylene propylene rubber (elastomer B), melt flow rate (190 ° C. 21.18 N)
5.5 g / 10 min, ethylene-α-olefin copolymer (elastomer C) having a density of 0.890 g / cm ³ , melt flow rate (190 ° C. 21.18 N) 20 g / 1
0 minute, linear low-density polyethylene resin (PE resin 1) having a density of 0.920 g / cm ³ , lubricant A as a lubricant, and tris (2,4-di-t-butylphenyl) as an antioxidant
Phosphite (phosphate prevention), tetrakis [methylene-
3- (3 ', 5'-di-t-butyl-4'-hydroxyphenyl) propionate] methane (protected from felic acid) and calcium stearate as a neutralizing agent, respectively, are shown in Table 6 below.
The mixture was placed in a tumbler mixer at the mixing ratio and mixing ratio described in 1), mixed for 10 minutes, melt-kneaded according to Examples 1 to 23, and pelletized. Using the pellets obtained in Comparative Examples 18 to 25, an integrated cap of a pull-open cap and a pull-open cap-hinge cap was molded, and the pull-open property, weld strength, deformation, mold release property, and hinge cap were obtained. Evaluation of the twist strength and the heat distortion temperature was performed. The results are shown in Table 6 below.

Examples 28 to 31 As Examples 28 to 31, as shown in Table 7 below,
PP1 resin, PE1 resin, elastomer A, nucleating agent sodium-2,2-methylene-bis- (4,6-di-t-
Butylphenyl) phosphate (nucleating agent A), Pt
-Butyl aluminum benzoate (nucleating agent B), 1,3,2,4-di- (paramethylbenzylidene) sorbitol as a clarifying agent, 1,3-bis (t-butylperoxyisopropyl) benzene (POX) , Lubricant A, tris (2,4-di-t-butylphenyl) phosphite (anti-phosphoric acid) as an antioxidant, tetrakis [methylene-3-
(3 ′, 5′-di-t-butyl-4′-hydroxyphenyl) propionate] methane (anti-ferric acid), calcium stearate as a neutralizing agent, in a blending formulation and a blending ratio shown in Table 7 below, to a tumbler mixer. After mixing for 10 minutes, the mixture was melt-kneaded and pelletized according to Examples 1 to 23. Using the pellets obtained in Examples 28 to 31, an integrated cap of a pull-open cap and a pull-open cap-hinge cap was molded, and the pull-open property, weld strength, deformation, mold release property, and hinge cap were formed. Evaluation of the twisting strength and heat deformation temperature was performed. The results are shown in Table 7 below.

[0021]

[Table 1]

[0022]

[Table 2]

[0023]

[Table 3]

[0024]

[Table 4]

[0025]

[Table 5]

[0026]

[Table 6]

[0027]

[Table 7]

As is clear from Tables 1, 2 and 3, the pull-open caps obtained in Examples 1 to 6 using the resin composition of the present invention have good pull-open properties, weld strength and deformation. The pull-open caps obtained in Examples 7 to 27 showed good pull-opening properties, weld strength, deformation, hinge cap twisting strength, heat deformation temperature, and excellent mold release. Shows shape.

As shown in Examples 13 to 16 in Table 2, if the resin composition of the pull-open cap is within the scope of the present invention and the mixing amount of the lubricant is within the scope of the present invention, the pull-open property and the weld strength are obtained. Thus, a pull-open cap having excellent deformation, mold releasability, hinge cap twisting strength, and heat deformation temperature can be obtained. Further, as shown in Examples 17 and 18 of Table 2 and Examples 19 to 23 of Table 3, the resin composition of the pull-open cap is within the scope of the present invention, and if the lubricant shown in the present invention is used, it can be used alone. However, even when used in combination, the effect does not change and excellent mold releasability is obtained.

As shown in Examples 24 and 25 in Table 3,
As long as the melt flow rate of the linear low-density polyethylene resin is within the range of the present invention, the effect is not impaired. As shown in Examples 26 and 27, the resin composition and the melt flow rate of the block copolymer are the same. Within this range, an excellent pull-open cap can be obtained.

The polypropylene copolymer resins shown in Table 4 fall within the scope of the present invention, but the resin compositions of Comparative Examples 1 to 8 in which the range of the elastomer or the linear low-density polyethylene resin is outside the scope of the present invention. The pull-open cap obtained in (1) is defective in at least one of the following items: pull-open property, weld strength, deformation, mold release property, twist strength, and heat deformation temperature.

As shown in Comparative Example 9 in Table 5, PP resin 1
When used alone, the molded product has good weld strength, deformation, mold releasability, hinge cap twisting strength, and thermal deformation temperature, but poor pull openability.

In Comparative Examples 10 and 11 in Table 5, since the elastomers of the present invention were not blended, the molded product obtained had good pull-opening properties, deformation, mold release properties, hinge strength, and heat deformation temperature. However, the weld strength was poor, and in Comparative Example 12, both the deformation and the heat deformation temperature were poor due to the excessive amount of the linear low density polyethylene resin added.

In Comparative Examples 13 to 15, since the propylene-ethylene block copolymer resin of the present invention was not used, the obtained molded article had good weld strength and mold releasing property, but had a pull-open property. One or more items of deformation, hinge cap strength, and heat deformation temperature are defective. In Comparative Examples 16 to 18 and 20 to 22, the mixing amount of the elastomer and the linear low-density polyethylene resin (PE resin 1) is within the range of the present invention, but propylene-
Since the ethylene copolymer is used, the obtained molded product has good weld strength, deformation, mold release properties, hinge cap twisting strength, and heat deformation temperature, but has poor pull open properties. In Comparative Examples 19 and 23, the elastomer and the linear low-density polyethylene resin (PE resin 1) used the resin of the present invention, but the amount of addition was excessive, so that the pull-open property and the mold release property were good. Some other items are bad.

Comparative Examples 24 and 25 are polypropylene resins,
The mixing ratio of the linear low-density polyethylene resin (PE resin 1) is within the range of the present invention, but since the elastomer is out of the range of the present invention, the obtained molded product has pull-opening property, deformation, and mold release property. , The hinge cap strength and the heat deformation temperature are good, but the weld strength is poor.

In Example 28 of Table 7, sodium-2,2'-methylene-bis- (4,6-di-t-butylphenyl) phosphite (nucleating agent A) was added to the resin composition of the present invention.
In Example 29, aluminum Pt-butyl benzoate (nucleating agent B), and in Example 30, a sorbitol-based clarifying agent 1,3,2,4-di- (paramethylbenzylidene) sorbitol (clarifying agent). In Example 31, 1,3-bis (t
-Butylperoxyisopropyl) benzene (POX)
However, if the resin composition is within the range of the present invention, the effect is not impaired, and excellent pull open properties, weld strength, deformation, mold release properties, heat deformation temperature and excellent. It was confirmed that a hinge hinge strength was obtained.

As apparent from the above description, the specific propylene-ethylene block copolymer resin, the specific elastomer or the specific propylene-ethylene block copolymer resin, the specific elastomer, The pull-open cap obtained by injection molding by blending a chain low-density polyethylene resin is 100-
Good pull-open property even when heat sterilized at 130 ° C,
Weld strength, deformation, mold releasability, heat deformation temperature, and when used as a hinge cap integrated cap, edible oil such as medical drinks such as infusion containers, salad oil, sesame oil, etc. , Soy sauce, sauce, vinegar, mirin, ponds, various dressings, pull-open caps having pull-open properties for foods such as fruit drinks, and integrated caps of pull-open cap and hinge cap.

[0038]

A specific propylene-ethylene block copolymer resin, a specific elastomer or a specific propylene-ethylene block copolymer resin, a specific elastomer and a linear low-density polyethylene resin are blended.
The integrated cap of the pull-open cap or pull-open cap-hinge cap of the present invention obtained by injection molding has a pull-open property, weld strength, deformation, mold release property, heat deformation temperature, and integration with the hinge cap. Since the cap has a significantly improved twisting strength when used as a cap, it can be suitably used for various applications, and is of great practical value.

Claims (6)

[Claims] 1. A melt flow rate (230 ° C. 21.1)
8N) 3 to 6 g at a melt flow rate (230 ° C. 21.18 N) based on 100 parts by weight of a propylene-ethylene block copolymer resin having a xylene extraction amount at 25 ° C. of 20% by weight or more at 3 to 100 g / 10 minutes. A pull-open cap or a pull-open cap-hinge cap formed by molding a resin composition containing 35 to 60 parts by weight of hydrogenated styrene / butadiene rubber / 10 minutes. 2. Hydrogenated styrene-butadiene rubber having a melt flow rate (230 ° C., 21.18 N) of 3 to 6 g / 10 minutes and 35 parts by weight of 35 parts by weight per 100 parts by weight of the propylene-ethylene block copolymer resin according to claim 1 is used. ~ 60 parts by weight,
Melt flow rate (190 ° C 21.18N) 5-5
0 g / 10 min, density 0.910 to 0.930 g / cm ²
A pull-open cap or a pull-open cap-hinge cap formed by molding a resin composition containing 5 to 25 parts by weight of a linear low-density polyethylene resin. 3. A propylene-ethylene block copolymer resin whose xylene extraction amount at 25 ° C. is 20% by weight or more.
The hydrogenated styrene / butadiene rubber according to claim 1, based on 100 parts by weight of a mixture consisting of 0 to 70% by weight and 50 to 30% by weight of the other propylene-ethylene block copolymer resin in total. In a proportion of 35 to 60 parts by weight or a hydrogenated styrene / butadiene rubber according to claim 2 in a proportion of 35 to 60 parts by weight and a linear low density polyethylene resin in a proportion of 5 to 25 parts by weight. An integrated cap of a pull-open cap or a pull-open cap-hinge cap formed by molding the composition. (4) 100 parts by weight of the resin composition according to any one of (1) and (2),
-Bis (t-butylperoxyisopropyl) benzene, 2,5-di-methyl-2,5-di (t-butylperoxy) hexane or at least one of these
An integrated cap of a pull-open cap or a pull-open cap-hinge cap formed by molding a resin composition mixed in a ratio of 1 to 0.1 part by weight. (5) A fatty acid ester, an aliphatic alcohol, a fatty acid dialkanolamide, an aliphatic dialkanolamine as a lubricant, relative to 100 parts by weight of the resin composition according to any one of (1) and (2). An integrated cap of a pull-open cap or a pull-open cap-hinge cap formed by molding a higher fatty acid amide or a resin composition in which one or more of these are blended in a ratio of 0.1 to 1 part by weight. 6. A pull-open cap or pull-open cap obtained by heat-treating a pull-open cap or a pull-open cap-hinge cap according to any one of claims 1 to 5 at 100 to 130 ° C. Puncap-An integrated cap with a hinge cap.