JPH02191166A - Container lid for germ free packing container - Google Patents

Abstract

PURPOSE:To obtain a container lid for a germ free packing container, which has an excellent flavor maintaining property for a packed content in the container and which has an easily openability by a method wherein a liner for the lid shell body is made of a polyolefin - ethylene propylene copolymer rubber composition which contains a lubricant, and the lid is used for sealing after being pre-sterilized with a sterilizing liquid. CONSTITUTION:A container lid for a germ free filling container is composed of a lid shell body and a liner which is applied on the inner surface of a top plate of the lid shell body by melt pressure molding and is thermally bonded on the inner surface of the top plate, extending the whole area. The liner is made of a polyolefin- ethylene propylene copolymer rubber composition which contains a lubricant, and the container lid is used for sealing after being pre-sterilized with a sterilizing liquid. For the lubricant, higher fatty acids, such as fatty acid amido or fatty acid ester, etc. can be counted, and a lubricant, which at least is held by adhesion on the surface layer or outer surface of the resin at the time of forming of the liner, is preferable. For such kind of lubricant, a higher fatty acid of which carbon number is at 6 or higher but 30 or lower is suitable. A sufficient effect to the cap opening torque can be frequently observed in lubricants which contain higher fatty acid in this range.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a container lid for aseptically filled containers, and in particular, to suppressing an abnormal increase in the opening torque of the container lid and improving the sterilization operation of the container lid. This invention relates to container lids for aseptic filling containers (plastic bottles, etc.) with excellent properties.

[Prior art]

Aseptic filling and packaging techniques are known as packaging techniques that are excellent in retaining the flavor of liquid contents. This technique generally involves the so-called ultra-high temperature sterilization method, in which the liquid contents are sterilized for 4 to 5 seconds at an ultra-high temperature of 100"C or higher and then sterilized.
υHT), a separately produced aseptic packaging material is treated with a sterilizing solution, and the previously sterilized liquid contents are filled into the packaging material and sealed. As the sterilizing liquid used for sterilizing packaging materials, those containing peracetic acid and/or hydrogen peroxide are used.

In the case of aseptic filling container products, it goes without saying that not only the container itself but also the container M (cap) used to seal it.
It is also necessary to sterilize.

[Problem that the invention seeks to solve]

However, the sterilization process for container lids is different from that for bottles.
Sterilization treatment 1 has several problems. In other words, in a container lid, a sealing material (gasket or liner) is placed on the inner surface of the top plate of the container lid shell in order to seal the gap with the bottle mouth.
is applied. There is often a small gap between this sealing material and the top plate, and the sterilizing solution may not penetrate into this area, resulting in sterilization failure, or even if the sterilizing solution does penetrate, the subsequent washing with water may be difficult. There is a problem in that the sterilizing liquid is not completely removed during operation and remains, contaminating the contents and reducing flavor retention.

Furthermore, when opening a sealed bottled product, it is necessary to create slippage between the bottle opening and the sealing material, and providing slipperiness to the sealing material is achieved by using the resin or rubber that forms the sealing material. This is done by blending a lubricant into the sealant and transferring the lubricant to the surface of the sealant.

However, when container lids are sterilized and then washed with water, the lubricant that has migrated to the surface of the sealing material is washed away, so the opening torque increases by three to five times that of without sterilization. caused a problem, -dan,
The increased opening torque does not easily recover to its normal value, and with conventional liner materials, even if the opening torque recovers to its normal value over time, it is said that the recovery of the opening torque to its normal value is slow. There is a problem.

Therefore, an object of the present invention is to solve the above-mentioned problems that occur when producing aseptically filled containers, to enable the container lids to be sterilized and subsequently washed with water, and to reduce the opening torque after these treatments. To provide a container lid for a sterile filling container, which allows rapid and reliable recovery from an abnormal increase in .

Another object of the present invention is to provide a container lid for an aseptic filling container that has excellent flavor retention properties for the contents packed in the container and also has open-open closure properties.

Means for Solving Problem C] In order to achieve the above object, the present invention provides a cap or shell-like lid shell, and a cap or shell that is formed by melt-pressing on the inner surface of the top plate of the lid shell, and The liner is thermally bonded over the entire inner surface of the top plate, and the liner is made of a polyolefin-ethylene propylene copolymer rubber composition containing a lubricant, and is used for sealing after being presterilized with a sterilizing solution. Features.

[Effect]

According to the present invention, the liner is applied to the inner surface of the top plate of the container lid shell by melt-press molding, is thermally bonded to the inner surface of the top plate, and is made of a polyolefin-ethylene propylene copolymer rubber composition containing a lubricant, This is based on the fact that when a container lid having such a liner is used as a lid for an aseptically filled container, the above-mentioned problems are solved at once.

First, the lid used in the present invention includes a liner formed on the inner surface of the top plate of the shell by melt extrusion molding and thermally bonded over the inner surface of the top plate.

Generally, in normal factory production, it is unavoidable that bacterial spores etc. adhere to the inner surface of the top plate of the shell, but in the lid used in the present invention, high temperature molten resin is supplied to the inner surface of the top plate, and this is removed. Since the liner is formed by pressure molding, there is an advantage that even if such bacterial spores are present on the inner surface of the top plate, they will be completely killed during molding.

In addition, since this liner is thermally bonded over the entire inner surface of the top plate, there is no gap formed between the liner and the top plate, which prevents microorganisms such as bacteria from entering between the two, or sterilization and treatment. Water washing treatment can be carried out efficiently and effectively within a short period of time.

As already pointed out, the abnormal increase in opening torque in aseptically filled containers is due to the fact that the lubricant that has migrated to the liner surface is washed away during sterilization and washing.

It has also been found that this abnormal increase in opening torque cannot be prevented simply by increasing the lubricant content in the liner forming composition that has been used heretofore.

However, when the liner is formed from a composition of polyolefin and ethylene propylene copolymer rubber mixed with a lubricant, even after sterilization and water washing, there is no problem with abnormal increases in opening torque. A rapid decrease is observed, and the regulation to normal values is effectively carried out. This fact was discovered only as an experimental fact, and its theoretical basis is still not sufficiently clear.

However, styrene-butadiene rubber (SBR),
Considering that other rubbers and elastomers such as styrene-isoprene-styrene copolymer (SIS) cannot achieve the effects of the present invention even when blended with polyolefin, polyolefin and ethylene-propylene copolymer rubber This is thought to be due to the unique lubricant transfer effect of

The lubricant is preferably one that has a transfer effect between the polyolefin and the ethylene-propylene copolymer rubber, and examples of lubricants that have a good transfer effect include those based on higher fatty acids such as fatty acid amides and fatty acid esters.

Further, the lubricant is preferably one that is compatible with the liner resin to some extent and is adhered and retained on the surface layer portion or outer surface of the resin at least during the formation of the liner.

Suitable lubricants include higher fatty acids with a carbon number of 6 or more and 30 or less, and lubricants containing higher fatty acids within these ranges are often found to have a sufficient effect on opening torque. It will be done.

Naturally, if the number of carbon atoms in the higher fatty acid in the lubricant is small, the lubricant will have a hydrophilic property (acidic part) relative to its lipophilic part.
This increases the compatibility between the polyolefin and the ethylene-propylene copolymer rubber, which tends to come out during molding of the liner and easily separate from the liner surface. For this reason, it is no longer possible to prevent an abnormal increase in the opening torque as in the conventional case. Taking this one step further, it is predicted that simply using an external lubricant will not prevent the abnormal increase in the opening torque. In addition, if the number of carbon atoms in the higher fatty acid in the lubricant is large, the proportion of the lipophilic portion becomes large and it becomes similar to an internal lubricant, resulting in poor transfer action and undesirable effects over time. Although the above-mentioned effects can be achieved, they can only be achieved by combining a polyolefin and an ethylene-propylene copolymer rubber composition.

Note that the present invention is particularly effective for manufacturing plastic containers. This is because plastic containers are unsuitable for in-container heat sterilization applications such as retort sterilization due to their thermal deformation problems.

[Preferred embodiments of the invention]

Hereinafter, preferred embodiment 1 of the present invention! Explain the situation.

In FIG. 1 showing an example of the container lid of the aseptic filling container according to the present invention, this cap shell 1 is formed by drawing a metal plate such as aluminum, and has a top plate portion (panel) 2. , and a circumferential side wall portion (skirt) 3.

The inner surface of this cap shell 1 has internal protection! A thermal adhesive paint layer 4 that also serves as a film is provided. The inner surface of the top plate portion 2 is provided with a liner generally designated by 5. This liner 5 is formed by press-molding a molten resin within the shell 1, and is strongly thermally bonded to the inner surface of the top plate portion 2 via a thermal bonding paint layer 4. It has a relatively thin center portion 6 and a relatively thick ring-shaped peripheral portion 7, and the ring-shaped peripheral portion 7 engages with the bottle mouth portion 10 for sealing.

In the liner for the container lid used in the present invention, the central part in contact with the contents is made thin, and the ring-shaped peripheral part in contact with the bottle mouth is made thick, while keeping the amount of lubricant transferred to the contents at a low value. This is useful for increasing the amount of lubricant transferred to the portion that comes into contact with the bottle mouth and reducing the opening torque.

From this point of view, the ratio of the thickness of the central part to the peripheral part is generally from 1:12 to 1:2, preferably from 1:10 to 1:3.

In the present invention, the liner 5 is formed from a polyolefin-ethylene propylene copolymer rubber composition containing a lubricant. The polyolefin and ethylene propylene copolymer rubber are preferably present in -S in a receiving ratio of 95:5 to 40:60, particularly 90:10 to 60:40. If the amount of polyolefin is less than the above range or greater than the above range, the lubricant cannot be sufficiently transferred to the sealed part after sterilization and washing, making it difficult to suppress the opening torque to an appropriate range. Cheap.

Furthermore, if the amount of the ethylene-propylene copolymer rubber is more than the above range or if the amount of the polyolefin is less than the above range, the melt extrudability and press moldability of the composition will deteriorate, which is not preferable.

The lubricant is preferably blended in an amount of 0.05 to 3.0% by weight, especially 0.1 to 1.5% by weight, based on the total amount of both types of combined materials.If the amount is less than the above range, the bottle will not open properly. It is difficult to regulate the torque to a relatively low range, and if the torque is greater than the above range, it will be disadvantageous in terms of lubricant transfer to the contents.

The polyolefin used for the liner includes polyethylene, polypropylene, and other low-density copolymers with side chains. Particularly preferred properties are low-density polymers, with a density of 0.925 to 0.925. 89
5 g/cc and a melt intex of 0.5 to 10 g/10 min are advantageously used.

On the other hand, as the ethylene propylene copolymer rubber, one having an ethylene content of 5 to 35 mol %, particularly IO to 30 mol % and a Mooney viscosity of 20 to 150 is advantageously used.

As the lubricant, fatty acid amides and glycerin fatty acid esters are particularly preferred, but it is of course possible to use other lubricants.

As fatty acid amides, (1) higher fatty acid amide oleyl palmitamide, stearyl erucamide, 2
-Stearomide ethyl stearate, etc. (2) Ethylene bis fatty acid amide N, N'-oleoylstearyl ethylenediamine, N
, N'-bis(2-hydroxyethyl)alkyl (C+
z to CI) amide, N,N''-bis(hydroxyethyl)lauroamide, N-alkyl (C36 to C
ps )) Oleic acid, etc. reacted with rimethylene diamine (3) Distearate, etc. of fatty acid jetanolamine di(hydroxyethyl) diethylenetriamine monoacetate, (4) Fatty acid ester of -valent, polyhydric alcohol n-butyl stearate, Hydrogenated rosin methyl ester, dibutyl sepatate, dioctyl sepatate (both 2-ethylhexyl and n-octyl), glycerin fatty acid ester glyceryl lactostearyl, pentaerythritol stearate, benquerythritol tetrastearate, sorbitan fatty acid ester polyethylene glycol mono Stearate, polyethylene glycol dilaurate, polyethylene glycol monooleate, polyethylene glycol dioleate, polyethylene glycol coconut fatty acid ester, polyethylene glycol tall oil fatty acid ester, ethanediol moncitate, 1,3-butanediol moncitrate, diethylene glycol stearin Acid esters (5) Triglycerides, wax hydrogenated edible oils and fats, cottonseed oil and other edible oils, glycerin esters of 1°2-hydroxystearic acid, hydrogenated fish oils, and the like.

In the present invention, when a liner is formed from a composition of a lubricant, a polyolefin, and an ethylene-propylene copolymer rubber, the combined action of the lubricant and this copolymer rubber composition causes the liner to be sterilized and returned to normal values. The effectiveness of regulation is certainly and even more clearly seen.

Among these effective lubricants, higher fatty acid-based lubricants such as fatty acid amides, fatty acid esters, and fatty acid salts as described above are preferred. In addition, the lubricant is preferably one that is compatible with the liner resin to some extent and adheres to and remains attached to the surface layer or outer surface of the resin at least during the formation of the liner. Suitable lubricants include higher fatty acids. The number of carbon atoms is 6 or more and 30 or less.

Higher fatty acids within these ranges are highly effective on the opening torque.

Note that the present invention is particularly effective for manufacturing plastic containers. This is because plastic containers are unsuitable for in-container heat sterilization applications such as retort sterilization due to their thermal deformation problems.

The liner is formed by uniformly melting and kneading the aforementioned composition, extruding it into a mass at a temperature of 180°C to 240°C, feeding this mass into a shell, and then pressing it with a cooled pressing die. Then, molding and thermal bonding are performed. As the thermal bonding paint, an epoxy-phenol paint or an epoxyamine paint containing oxidized polyethylene or acid-modified polyethylene is used.

Next, a method for sterilizing a container lid of an aseptically filled container according to the present invention will be explained.

FIG. 2 is a schematic explanatory diagram of an apparatus in which the method for sterilizing container lids of aseptically filled containers according to the present invention is used.

As shown in FIG. 2, a container lid supply device 12 is provided on the base floor 10, and the container lids 1.1, . . . described above are fed into a supply hopper 16 of the container lid supply device 12. . The container M1 of the supply hopper 16 is supplied to the supply hopper 22 of the sterilizer 20 via the lifting conveyor 18.

The container lid L of the supply hopper 22 is introduced into the main body 24 of the sterilizer 20, and as shown in FIG.
One continuous conveyance line 26 is formed in a 99-fold pattern. The inlet portion 26A of the continuous conveyance line 26 is connected to the supply hopper 22.
The outlet portion 26B is connected to an assembly device (not shown) for assembling aseptic filling containers.

FIG. 4(A) is a sectional view of section A (straight section of continuous conveyance line 26) in FIG. 3. As shown in FIG. 4(A), the continuous conveyance line 26 consists of a pair of guide members 28, 28,
The guide member 28.28 has a cross-section shaped like a substantially square shape. The lower end of the container M1 is the support surface 2 of the guide material 28.
8A and 28A, and the side peripheral surface of the container 11 is supported by the side walls 28B and 28C of the respective guide members 28.2B.
Movement is regulated. Further, the movement of the container M1 is restricted by the upper lid 30 of the main body 24.

FIG. 4(B) shows part B of FIG. 3 (0 of continuous conveyance line 26).
297 part) is a plan view. As shown in FIG. 4(B), the 0297 section of the continuous conveyance line 26 has a pair of guide materials 28
．． 28 is integrally formed through a portion of the support surface 28A. Further, the guide material side wall 28B is formed as an outer circumferential wall of the 0297 section, and the guide material side wall 28C is formed as an inner circumferential wall of the 0297 section. The container M1 performs U-town by being guided by the outer circumferential wall and inner circumferential wall.

Further, below between the guide members 28, 28, there are spray nozzles 32, 32, 32, 32, 32, 32, 32, 34, 34, 34, 34, 34, 34, sterile spray nozzles for sterile cleaning solution for rinsing.
,... are provided. As shown in Fig. 5, each spray nozzle 32, 34 sprays a shower 36, 38 of a sterilizing liquid or a sterile cleaning liquid from an oblique direction into the container lid, and the inner surface of the container Ml is in contact with the sterilizing liquid. The product is sterilized using a sterile cleaning solution and then washed with water using a sterile cleaning solution.

Further, each spray liquid is ejected diagonally toward the conveyance direction, and the lightweight container M1 is attached to the guide material 28.2 described above.
8 and the upper lid 30, the spray liquid is moved along the continuous conveyance line 26 by the ejection force of each spray liquid.

The sterilizing liquid used is hot water, hydrogen peroxide, peracetic acid, Na0C.
1, CzHsOH, etc. are used, especially those containing peracetic acid and/or hydrogen peroxide, and a suitable sterilizing solution composition is peracetic acid (C)I, C00)I) and/or hydrogen peroxide (H2O2 ) to 0. 5 to 5. It is contained at a concentration of 0%. Furthermore, as the sterile cleaning solution, sterile water or alcohol is used, and hot water, NaOH aqueous solution, etc. are also used.

The spray nozzles 32, 34 can also change the angle and direction of the shower 36, 38 by means of joint members according to known techniques.

In such a method for sterilizing container lids of aseptically filled containers according to the present invention, container lids 1 are continuously supplied from the supply hopper 22 to the sterilizer 20. The supplied container lid 1 receives a shower 3 of sterilizing liquid from spray nozzles 32, 32, .
6 to be sterilized. Further, at this time, the container Iff is moved along the conveyance direction of the continuous conveyance line 26 by the jetting force of the sterilizing liquid. The moved container lid 1 is rinsed with a shower 38 of sterile cleaning liquid from the spray nozzle 34 at the rear stage. At this time as well, the container lid 1 is moved in the transport direction by the jet force of the sterile cleaning liquid and is transported to the outlet of the sterilizer 20.

In this way, the container M1 is moved along the continuous conveyance line 26 by the ejection pressure of the spray liquid from the spray nozzles 32, 34, so that the conveyor etc. are moved along the continuous conveyance line 26.
There is no need to provide it at 6. Therefore, there is no need for a gripping device on the conveyor, and the container Ml can freely rotate within the guide 28.28, and can fully receive the liquid from the spray nozzle 32.34. In addition, as a matter of course, there is no need to operate the conveyor, and the continuous conveyor line 26
The sterilizer 20 can be formed compactly by freeing up space. In this way, since the container lids are moved along the continuous conveyance line using the blowing pressure of sterilizing liquid, etc., the container lids are reliably sterilized during transportation, and the sterilization processing space is downsized. The operating cost of equipment etc. can be lowered.

In addition, in such a configuration, the spray nozzle 32.3
4 may be provided with a nozzle pressure adjustment device to adjust the ejection pressure of the spray liquid.By adjusting such a adjustment device, the moving speed of the container M1 in the continuous conveyance line 26 can be adjusted. .

The nozzle pressure is appropriately determined depending on the weight of the container lid 1, but is usually used in the range of 0.5 to 5 kg/cj.

Moreover, although the continuous conveyance line 26 of the sterilizer 20 is provided horizontally, it is not limited to this, and may be provided vertically depending on the case.

The container lid 1 sterilized in this manner is used for capping and sealing a container filled with sterilized contents sterilized by a UHT device.

In the present invention, a two-wheel stretch blow-molded bottle made of polyethylene terephthalate (PET) is preferably used as the plastic container. Instead of this PET container, a blow molded or stretch blow molded container made of other plastics such as polypropylene or polycarbonate may be used.

Sterilization and washing of the containers are carried out by methods known per se.

〔Effect of the invention〕

According to the present invention, by supplying high-temperature molten resin to the inner surface of the top plate and press-molding it to form a liner that is in close contact with the top plate over the entire inner surface, the liner and the top plate can be bonded together. No gaps are formed between the two, so there is no problem of bacteria or other microorganisms invading between the two, or that the sterilizing solution remains in the gaps, making it possible to sterilize and wash container lids in a short time. It can be done efficiently and effectively within the time period.

In addition, by using a lid with a liner made from a composition of polyolefin and ethylene-propylene copolymer rubber mixed with a lubricant, even after sterilization and water washing, the opening torque is maintained over time. regulation to normal values has become effective. Furthermore, if the lubricant is a higher fatty acid-based lubricant, recovery from an abnormal value to a normal value is quick, and regulation to a normal value is effectively performed.

〔Example〕

The invention is illustrated by the following example.

Various liner materials (compositions are as shown below) were in-shell molded onto a 38 mm PP cap made of aluminum. The shape of the liner at this time was a flat type, and the thickness of the sealed portion of the liner was set to 1.0 am.

(1) Resin and lubricant LDPE used: Low density polyethylene density 0.917, M
l 7 SBR: Styrene butadiene rubber SIS: Styrene isoprene styrene copolymer EPR:
Ethylene propylene copolymer EVA: Ethylene vinyl acetate copolymer (VA content 1O%) Lubricant Nioleic acid amide (2) Composition Example I of liner material LDPE (80 parts by weight) + EPR (20 parts by weight) Ten lubricants (0, 4 parts by weight) Comparative example! LDPE (80 parts by weight) + 5BR (20 parts by weight) lubricant (0.4 parts by weight) Comparative example 2 LDPE (80 parts by weight) + 5TS (20 parts by weight) lubricant (0.4 parts by weight) Comparative example 3 LDPE ( 80 parts by weight) + 5IS (20 parts by weight) ten lubricants (1,2 parts) Comparative Example 4 EVA (100 parts by weight) ten lubricants (0,4 parts by weight) Comparative Example 5 LDPE (100 parts by weight) ten lubricants ( A 38 PET bottle (content M 1.5 g) rinsed with water (0.4i parts) was camped, and the opening torque was measured over time.
For comparison, camping and opening torque were similarly measured for caps whose inner surfaces were not sterilized. The results are shown in Table 1.

In addition, titanium white and stabilizers were used within the usual range.

The inner surface of the cap, which is in-shell molded with the above liner material, is sterilized by shower spraying for 3 minutes with a diluted sterilizing solution of peracetic acid and hydrogen peroxide mixture, rinsed with tap water, then sterilized with the same sterilizing solution, and then sterilized with the above sterilizing solution.

[Brief explanation of the drawing]

Figure 1 is a side sectional view of the container lid of the aseptic filling container according to the present invention, Figure 2 is an explanatory diagram of a sterilizer with a capacity of 8M for aseptic filling containers, and Figure 3 is an illustration of the sterilizer shown in Figure 2 with the top lid removed. Fig. 4 (A) is a cross-sectional view of section A in Fig. 3, Fig. 3 (B) is a plan view when
is a plan view of section B in FIG. 3, and FIG. 5 is a schematic side view of the continuous conveyance line of the sterilizer. l...-cap shell, 2...-top plate, 3--
Circumferential side wall portion, 4.-thermal adhesive paint layer, 5. Liner 10...-container opening. Applicant: Japan Crown Cork Co., Ltd.

Claims (2)

[Claims] (1) Consisting of a cap or shell-shaped lid shell, and a liner applied to the inner surface of the top plate of the lid shell by melt-press molding and thermally bonded over the entire inner surface of the top plate,
A container lid for an aseptically filled container, wherein the liner is made of a polyolefin-ethylene propylene copolymer rubber composition containing a lubricant, and is used for sealing after pre-sterilizing with a sterilizing liquid. (2) The container lid for an aseptically filled container according to claim 1, wherein the lubricant is a higher fatty acid-based lubricant, and the higher fatty acid has 6 to 30 carbon atoms.