JPH02269648A - Bottle with pull-off-cap and its composition - Google Patents

Abstract

PURPOSE:To open a cap with a weak pulling force and increase a heat-resistant, by using a composite material including a highly crystalline polypropylene resin, a polyolefin elastomer diluted with oil and polyolefin wax. CONSTITUTION:A resin made of a least an easily pull-off part 4 at a cap 1 is constituted by a composite material including a highly crystalline polypropylene resin, a polyolefin elastomer diluted with oil, and polyolefin wax. The cap 1, a part acted by an external force (finger ring 3), the easily pulling-off part 4 and a bar piece 1 are preferably made of this composite material. In this way, a pull-off cap with an excellent heat-resistant, pulling-off and molding properties can be obtained.

Description

[Detailed Description of the Invention] [Technical Field] The present invention relates to a container with a pull-off cap, which is used for a container made of resin used for soft drinks, etc., and which can be easily torn off and opened by a person when in use. The present invention relates to compositions to be used, and particularly to containers and compositions with excellent heat resistance, tearability, and moldability.

<Prior art and its problems> Conventionally, the opening part of a resin container is provided with a finger rest part and a continuous notch part, etc., and an external force is applied by a human finger to open the cap or unseal the container. Containers that make this possible are already known.

However, in conventional containers, the cutout portion is difficult to tear off, and the force required to tear it off is too great, which may even damage the container. If the notch etc. are made large enough to be easily torn off, there is a risk that the notch etc. will be damaged by external force during transportation or storage, resulting in leakage of the contents.

<Problems to be Solved by the Invention> The purpose of the present invention is to solve the problems in the prior art and provide a container with a pull-off cap that has excellent heat resistance, tearability, and moldability, and a composition used therein. do.

Means for Solving the Problems> That is, the present invention provides a pull-off cap having a portion to which an external force is applied, and an easy-to-tear portion that is continuous with the portion and is broken by the external force, the pull-off cap having at least the pull-off portion. A container with a pull-off cap, characterized in that the easily tearable part is made of a composition containing a highly crystalline polypropylene resin (A), an oil-extended polyolefin elastomer (B), and a polyolefin wax (C). provide.

In addition, high crystalline polypropylene resin (A) 30 to 50
Weight parts and oil-extended polyolefin elastomer (B) 30~
and 5 to 20 parts by weight of a polyolefin wax (C), and is characterized in that it is used in a container with a pull-off cap.

Here, the oil-extended polyolefin elastomer (B) preferably contains 10 to 50 parts by weight of petroleum oil based on 100 parts by weight of the polyolefin elastomer.

Further, it is preferable that the polyolefin wax (C) is a mixed wax of a polypropylene wax and a polyethylene wax.

The present invention will be explained in detail below.

The container of the present invention is a container that has a lid that seals like a soft drink bottle, and has a portion of the lid to which an external force is applied, and a portion that is continuous with the portion and is broken by the external force. Any structure may be used as long as the container has an easily tearable part and can be easily torn open by a person during use.

A preferred example of the configuration is shown in FIGS. 1 and 2.

The lid body 1 has a finger ring 3 that is a portion to which an external force is applied. As shown in FIG. 1, the finger ring 3 is an annular portion, and is configured such that an external force is applied when a person places a finger inside the annular ring and pulls it. The shape of the finger ring 3 may be a tongue shape or the like other than an annular shape.

The finger ring 3 has a portion 4 that can be easily torn off via the rod-shaped portion 2.
It is continuous. The rod-shaped part 2 is not particularly necessary, but if the finger ring 3 is directly continuous with the easily torn off part 4, it will be difficult to put your finger on it.
It is preferable that the space be located an appropriate distance away from the ground in the vertical direction.

The easy-to-tear portion 4 is a linear portion that causes the lid 1 to break due to an external force applied to the finger ring 3, and has a thin wall portion on the front and/or back surface of the lid 1. When the lid 1 seals the container 6, the lid is not broken and is integrated with the lid 1, and when an external force is applied to the finger ring 3, it breaks and separates from the lid 1. Open the container 6.

In order to reclose the container 6 that has been opened by breaking the easily torn off part 4, the lid body 1 is provided with an external thread 5, for example, and an internal thread that fits into the external thread 5 is provided. It is sufficient to have a configuration in which a cap with an internal thread is screwed into the cap.

In the container of the present invention, the resin constituting at least the easily tearable portion 4 of the lid 1 described above is composed of the following composition of the present invention. Preferably, the lid 1, the part to which external force is applied (finger ring 3), the easily torn off part 4, and the rod-shaped body 2 are made of the following composition.

The composition of the present invention is a highly crystalline polypropylene resin (A
), an oil-extended polyolefin elastomer (B) and a polyolefin wax (C) as essential components.

The high crystalline polypropylene resin (A) is a homopolymer or a copolymer of propylene and one or more of the following 1-olefins as an axial polymer, and is produced by random copolymerization or by block copolymerization. It includes any of the following. Its MFR (230t) is 10-100
g/10 ml n, preferably 10-60
g/10 min, [η] is 1.2 to 2.5
dIl/g, preferably 1.6-2.5 dIL/g (1
35°C, decahydronaphthalene solution).

Examples of 1-olefins include ethylene, propylene, and 1-olefin.
Butene, 1-pentene, 3-methyl-1-butene, 1-
hexene, 3-methyl-1-pentene, 4-methyl-1
-pentene and 1-octene.

The oil-extended polyolefin elastomer (B) is a substantially amorphous or low-crystalline copolymer obtained by copolymerizing two or more of the above-mentioned 1-olefins, and contains a petroleum softener (processing oil). It is an oil exhibition.

[η] of the axial polymer is selected to be 1.4 to 4.0 dJ2/g, preferably 2.0 to 3.0 dJZ/g (135°C, decalin solution). In component (B), it is preferable that the ratios (molar ratios) of the constituent units of the axial polymer are close to each other.

The range is 50 to 80 units in the larger unit based on the copolymer.
mol %, preferably 50 to 65 mol %. Even when the axial polymer is a ternary or higher multicomponent polymer, it can be used as component (B) in the present invention as long as the maximum number of units is within the above range.

X-ray diffraction of axial polymer (using copper target as anticathode,
The crystallinity according to the wavelength 1.54 conditions) method is selected to be 15% or less, preferably 5% or less.

Preferred shaft polymers are ethylene/propylene rubber, propylene/ethylene rubber, and mixtures thereof.

The oil used for oil extension is a petroleum softener, and examples thereof include paraffin oil, naphthenic oil, and aromatic oil. Particularly preferred is a paraffinic process oil, with naphthenic content of 20 to 40% by weight.
50% by weight or more of paraffinic type, 20% by weight of aromatic type
Those having the following composition, heat resistance, weather resistance, and a high flash point are preferred. For example, a process oil having a viscosity of 380 at 40°C and a viscosity of 30 at 100°C is preferred.

The amount of oil extended is preferably 10 to 50 parts by weight per 100 parts by weight of the polyolefin elastomer. When the oil extension amount is within this range, the flowability of the polyolefin elastomer during melt molding can be improved, and the dispersibility of the polyolefin elastomer in the composition is improved, giving good tearability. be able to.

The amount of oil-extended polyolefin elastomer (B) varies depending on the type of high-crystalline polypropylene resin used, but is 40 to 40% relative to the homopolymerized polypropylene resin.
65wt%, block copolymerized polypropylene (rubber amount 1
It is preferable to set the content to 30 to 55 wt% compared to 0 wt%).

Within this range, tearability is excellent.

The polyolefin wax (C) has a crystalline homopolymer or two or more types of crystalline copolymers of the 1-olefin as an axis polymer. Its [η] is 0.04~
tdIL/g, preferably 0.2-0.5 dλ/g (1
35°C, decalin solvent), melting point (T, ) by DSC method
The temperature is selected to be 90-138°C, preferably 110-125°C.

Preferred as component (C) are polyethylene wax and polypropylene wax. Further, a mixed system of polypropylene wax and polyethylene wax is preferable from the viewpoint of a balance between the moldability improvement effect and the thin film strength of the easily tearable portion 4.

Further, when two or more of the above waxes are used in combination, an even more excellent composition can be obtained.

Component (C) may be directly polymerized or may be obtained by modifying the polymer.

Each component (A), (B) and (C) constituting the composition of the present invention
) may be modified depending on the intended use, or may be blended with a required amount of a modified polymer.

For example, by grafting polymerizable vinyl chloride or the like, adhesiveness, printability, etc. are improved. Preferred examples include esters of maleic anhydride, acrylic acid or methacrylic acid.

Further, oxidation can also be employed as another modification means, and of course a combination of oxidation and grafting with maleic anhydride can also be used.

In some cases, the problem can be solved by polarizing the surface of the molded article by corona discharge treatment, flame treatment, etc. after molding to impart adhesiveness, printability, etc.

The amount of polyethylene wax (C) added is preferably 5 to 20 wt% of the total composition. Within this range, the composition has good moldability.

The method for manufacturing the container of the present invention is not particularly limited. Preferably, predetermined amounts of polypropylene, oil-extended polyolefin elastomer, and polyolefin wax are sufficiently mixed in a mixer at room temperature. Alternatively, each component may be dissolved in an appropriate solvent and mixed.

Compounding pellets are created from the mixture at a granulation temperature of 180° C. to 220° C. using a melt mixer such as a single-screw extruder or a twin-screw extruder. This composition pellet is placed in an injection molding machine and injection molded into the shape of a container 6 shown in FIG. 2 as an example at a molding temperature of 180 DEG C. to 220 DEG C.

<Examples> The present invention will be specifically explained below using Examples, but the present invention is not limited thereto.

Specified amounts of each component shown in Table 1 were weighed out and mixed at room temperature using a mixer such as a tumbler or a Henschel mixer to form a composition. This composition was granulated using an extruder at a temperature of 20
A compound pellet was prepared at 0°C. This compounding pellet was formed into a container 6 having the shape shown in FIG. 2 using an injection molding machine at a molding temperature of 220°C.

Separately, for comparison, a container 6 having the shape shown in FIG. 2 was produced by injection molding in the same manner using the polymer shown in Table 1.

The following tests were conducted and evaluated on the prepared containers, and the results are shown in Table 1.

(1) Opening force (tearing force) Using a special jig with a tensile tester Fix the cap with the ring part (finger 200 as if pulling up the hanging ring) Pull open the cap with mm/mtn, and then It was evaluated based on the force required.

(2) Heat resistance Steel controlled at 110℃ Put it in the oven for 1 hour and check visually. The changes in shape were observed.

<Effects of the Invention> The container of the present invention is made of the composition of the present invention containing a highly crystalline polypropylene resin, an oil-extended polyolefin elastomer, and a polyolefin wax. It can be opened with lower tearing force than when using
It also has high heat resistance.

[Brief explanation of drawings]

FIG. 1 is a front view showing one embodiment of the present invention, and FIG.
It is an AA line arrow view of a figure. FIG. 2 is a partially cutaway side view showing one embodiment of the present invention. Explanation of symbols 1...Lid body, 2...Bar-shaped body, 3...Finger ring, 4...Easy to tear part, 5...Outer thread,...Container

Claims (6)

[Claims] (1) A pull-off cap having a part to which an external force is applied and an easy-to-tear part that is continuous with the part and is broken by the external force, wherein at least the easy-to-tear part is made of high-crystalline polypropylene-based resin. A container with a pull-off cap, comprising a composition containing (A), an oil-extended polyolefin elastomer (B), and a polyolefin wax (C). (2) The oil-extended polyolefin elastomer (
2. The container with a pull-off cap according to claim 1, wherein B) contains 10 to 50 parts by weight of petroleum oil based on 100 parts by weight of the polyolefin elastomer. (3) The container with a pull-off cap according to claim 1 or 2, wherein the polyolefin wax (C) is a mixed wax of a polypropylene wax and a polyethylene wax. (4) High crystalline polypropylene resin (A) 30-50
30 to 65 parts by weight of an oil-extended polyolefin elastomer (B), and 5 to 20 parts by weight of a polyolefin wax (C), and is characterized in that it is used in a container with a pull-off cap. thing. (5) The oil-extended polyolefin elastomer (
5. The composition according to claim 4, wherein B) contains 10 to 50 parts by weight of petroleum oil based on 100 parts by weight of the polyolefin elastomer. (6) The composition according to claim 4 or 5, wherein the polyolefin wax (C) is a mixed wax of a polypropylene wax and a polyethylene wax.